RFC3867

From RFC-Wiki

Network Working Group Y. Kawatsura Request for Comments: 3867 Hitachi Category: Informational M. Hiroya

                                                  Technoinfo Service
                                                         H. Beykirch
                                                         Atos Origin
                                                       November 2004
   Payment Application Programmers Interface (API) for v1.0
             Internet Open Trading Protocol (IOTP)

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2004).

Abstract

The Internet Open Trading Protocol (IOTP) provides a data exchange format for trading purposes while integrating existing pure payment protocols seamlessly. This motivates the multiple layered system architecture which consists of at least some generic IOTP application core and multiple specific payment modules.

This document addresses a common interface between the IOTP application core and the payment modules, enabling the interoperability between these kinds of modules. Furthermore, such an interface provides the foundations for a plug-in-mechanism in actual implementations of IOTP application cores.

Such interfaces exist at the Consumers', the Merchants' and the Payment Handlers' installations connecting the IOTP application core and the payment software components/legacy systems.

Contents

Introduction

Common network technologies are based on standardized and established Internet technologies. The Internet technologies provide mechanisms and tools for presentation, application development, network infrastructure, security, and basic data exchange.

Due to the presence of already installed trading roles' systems with their own interfaces (Internet shop, order management, payment, billing, and delivery management systems, or financial institute's legacy systems), IOTP has been limited to the common external interface over the Internet. However, some of these internal interfaces might be also standardized for better integration of IOTP aware components with of the existing infrastructure and its cost effective reuse. For more information on IOTP, see [IOTP] and [IOTPBOOK].

The typical Payment Handlers (i.e., financial institutes or near-bank organizations) as well as Merchants require an IOTP aware application that easily fits into their existing financial infrastructure. The Payment Handler might even insist on the reuse of special in-house solutions for some subtasks of the IOTP aware application, e.g., reflecting their cryptography modules, gateway interfaces, or physical environment. Therefore, their IOTP aware implementation really requires such clear internal interfaces.

More important, consumers demand modularization and clear internal interfaces: Their IOTP application aims at the support of multiple payment methods. Consumers prefer the flexible use of different seamless integrating payment methods within one trading application with nearly identical behavior and user interface. The existence of a well-defined interface enables payment software developers to bolt on their components to other developer's general IOTP Application Core.

Initially, this consideration leads to the two-level layered view of the IOTP software for each role, consisting of:

o some generic IOTP system component, the so-called IOTP application

  core - providing IOTP based gateway services and generic business
  logic and

o the trading roles' specific back-end systems implementing the

  specific trading transaction types' functionality.

In order to isolate the changes on the infrastructure, the IOTP trading application has been three-layered:

o the IOTP Application Core processes the generic parts of the IOTP

  transaction and holds the connection to the Internet,

o the Existing Legacy System or Existing Payment Software which

  processes the actual transaction type, and particular payment
  transaction, and

o the IOTP Middle-ware or IOTP Payment Bridge which glues the other

  two possibly incompatible components.  It brokers between the
  specific interface of the Existing Legacy System and the
  standardized interfaces of the IOTP Application Core.

As IOTP extends payment schemes to a trading scheme, primarily, this document focuses on payment modules, i.e., the interface between the IOTP Payment Bridge and the IOTP Application Core. It provides a standard method for exchanging payment protocol messages between the parties involved in a payment. But, it does not specify any interface for order or delivery processing.

Such a Payment Application Programmers Interface (API) must suit for a broad range of payment methods: (1) software based like Credit Card SET or CyberCoin, (2) chip card based like Mondex or GeldKarte, and (3) mimicries of typical and traditional payment methods like money transfer, direct debit, deposit, withdrawal, money exchange and value points. It should support both payments with explicit consumer acknowledge and automatic repeated payments, which have been consumer approved in advance. For more information on SET, see [SET].

The following discussion focuses on the Consumer's point of view and uses the associated terminology. When switching to Merchants' or Delivery Handlers' IOTP aware applications, the payment related components should be implicitly renamed by Existing Legacy Systems to the IOTP Middle-ware.

The next two sub-sections describe the general payment scenario and several assumptions about the coarsely sketched software components.

Section 2 illustrates the payment transaction progress and message flow of different kinds of transaction behavior. Sections 3 to 4 provide the details of the API functions and Section 5 elaborates the call back interface.

General payment phases

The following table sketches the four logical steps of many payment schemes. The preceding agreements about the goods, payment method, purchase amount, or delivery rules are omitted.

Payment State Party Example Behavior


----- ----------------

Mutual Payment Handler Generation of identification Authentication request, solvency request, or and some nonce Initialization Consumer Responses to the requests and

                                generation of own nonce

Authorization Payment Handler Generation of the authorization

                                request (for consumer)
              Consumer          Agreement to payment (by
                                reservation of the Consumer's
                                e-money)
              Payment Handler   Acceptance or rejection of the
                                agreement (consumer's
                                authorization response),
                                generation of the authorization
                                request (for issuer/acquirer),
                                and processing of its response

Capture Generation of the capture

                                request (for issuer/acquirer)
              Consumer          Is charged
              Payment Handler   Acceptance or rejection of the
                                e-money, close of the payment
                                transaction

Reversal On rejection (online/delayed):

                                generation of the reversal data
              Consumer          Receipt of the refund

However, some payment schemes:

o limit themselves to one-sided authentication, o perform off-line authorization without any referral to any

  issuer/acquirer,

o apply capture processing in batch mode, or o do not distinguish between authorization and capture, o lack an inbound mechanism for reversals or implement a limited

  variant.

This model applies not only to payments at the typical points of sales but extends to refunds, deposits, withdrawals, electronic cheques, direct debits, and money transfers.

Assumptions

In outline, the IOTP Payment Bridge processes some input sequence of payment protocol messages being forwarded by the IOTP Application Core. It (1) disassembles the messages, (2) maps them onto the formats of the Existing Payment Software, (3) assembles its responses, and (4) returns another sequence of payment protocol messages that is mostly intended for transparent transmission by the IOTP Application Core to some IOTP aware remote party. Normally, this process continues between the two parties until the Payment Handler's Payment API signals the payment termination. Exceptionally, each system component may signal failures.

The relationship between the aforementioned components is illustrated in the following figure. These components might be related to each other in a flexible n-to-m-manner:

o One IOTP Application Core may manage multiple IOTP Payment Bridges

  and the latter might be shared between multiple IOTP Application
  Cores.

o Each Payment Bridge may manage multiple Existing Payment Software

  modules and the latter might be shared between multiple Payment
  Bridges.

o Each Existing Payment Software may manage multiple payment schemes

  (e.g., SET) and the latter might be supported by multiple Existing
  Payment Software modules.  For more information on SET see [SET].

o Each payment scheme may support multiple payment instruments

  (e.g., particular card) or methods (e.g., Visa via SET) and the
  latter might be shared by multiple Existing Payment Software
  Components.
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IOTP client (consumer) <---------------> IOTP server (merchant) ( contains Internet ( contains IOTP Application Core) IOTP Application Core)

     ^                                          ^
     | IOTP Payment                             | IOTP Payment
     |    API                                   |    API
     v                                          v

IOTP Payment Bridge IOTP Payment Bridge

    ^                                           ^
    | Existing Payment APIs, e.g.,              |
    | SET, Mondex, etc.                         |
    v                                           v

Existing Payment Software Existing Payment Software

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
             Figure 1: Relationship of the Components

The Payment API considers the following transaction types of Baseline IOTP:

  o  Baseline Purchase,
  o  Baseline Refund,
  o  Baseline Value Exchange,
  o  Baseline Withdrawal, and
  o  Baseline (Payment) Inquiry.

For more information on Baseline IOTP, see [IOTP] and [IOTPBOOK].

First, the authors' vision of the IOTP aware application's and its main components' capabilities are clarified: On the one hand, the Payment API should be quite powerful and flexible for sufficient connection of the generic and specific components. On the other hand, the Payment API should not be overloaded with nice-to-haves being unsupported by Existing Payment Software.

Despite the strong similarities on the processing of successful payments, failure resolution and inquiry capabilities differ extremely among different payment schemes. These aspects may even vary between different payment instrument using the same payment schemes. Additionally, the specific requirements of Consumers, Merchants and Payment Handlers add variance and complexity. Therefore, it is envisioned that the IOTP Application Core provides only very basic inquiry mechanisms while complex and payment scheme specific inquiries, failure analysis, and failure resolution are fully deferred to the actual Existing Payment Software - including the user interface.

The IOTP Application Core processes payments transparently, i.e., it forwards the wrapped payment scheme specific messages to the associated IOTP Payment Bridge/Existing Payment Software. The Existing Payment Software might even use these messages for inbound failure resolution. It reports only the final payment status to the IOTP Application Core or some intermediate - might be also final - status on abnormal interruption.

The IOTP Application Core implements the generic and payment scheme independent part of the IOTP transaction processing and provides the suitable user interface. Focusing on payment related tasks, it

o manages the registered IOTP Payment Bridges and provides a

  mechanism for their registration - the latter is omitted by this
  document.

o assumes that any IOTP Payment Bridge is a passive component, i.e.,

  it strictly awaits input data and generates one response to each
  request,

o supports the payment negotiation (Consumer: selection of the

  actual payment instrument or method; Merchant: selection of the
  payment methods being offered to the Consumer) preceding the
  payment request,

o requests additional payment specific support from the Existing

  Payment Software via the selected and registered the IOTP Payment
  Bridge,

o initializes and terminates the Existing Payment Software via the

  IOTP Payment Bridge,

o inquires authentication data (for subsequent request or response)

  from the Existing Payment Software, specific authentication
  component - omitted in this document - or Consumer (by a suitable
  user interface),

o supervises the online transaction process and traces its progress,

o stores the transaction data being exchanged over the IOTP wire -

  payment scheme specific data is handled transparently,

o relates each payment transaction with multiple payment parameters

  (IOTP Transaction Identifier, Trading Protocol Options, Payment
  Instrument/Method, Offer Response, IOTP Payment Bridge, and Wallet
  Identifier, associated remote Parties).  The relation might be
  lowered to the party's Payment Identifier, IOTP Payment Bridge,
  Wallet Identifier, and the remote parties when the actual payment
  transaction has been successfully started.

o implements a payment transaction progress indicator,

o enables the inquiry of pending and completed payment transactions,

o implements generic dialogs, e.g., brand selection, payment

  acknowledge, payment suspension / cancellation, receipt
  visualization, basic transaction inquiry, balance inquiry, or
  receipt validation,

o defers payment specific processing, supervision, validation, and

  error resolution to the Existing Payment Software.  It is
  expected, that the Existing Payment Software will try to resolve
  many errors first by the extended exchange of Payment Exchange
  messages.  The most significant and visible failures arise from
  sudden unavailability or lapses of the local or opposing payment
  component.

o supports the invocation of any Existing Payment Software in an

  interactive mode, which might be used (1) for the payment scheme
  specific post-processing of a (set of) payment transactions, (2)
  for the analysis of a payment instrument, (3) for the registration
  of a new payment instrument/scheme, or (4) re-configuration of a
  payment instrument/scheme.

o exports call back functions for use by the IOTP Payment Bridge or

  Existing Payment Software for progress indication.

In addition, the IOTP Application Core

o manages the IOTP message components and IOTP message blocks

  exchanged during the transaction which may be referenced and
  accessed during the processing of subsequent messages, e.g., for
  signature verification.  In particular, it stores named Packaged
  Content elements exchanged during payments.

o manages several kinds of identifiers, i.e., transaction, message,

  component, and block identifiers,

o implements a message caching mechanism,

o detects time-outs at the protocol and API level reflecting the

  communication with both the IOTP aware remote party and the
  Payment API aware local periphery, e.g., chip card (reader) may
  raise time-outs.

However, the IOTP Payment Bridge and Existing Payment Software do not have to rely on all of these IOTP Application Core's capabilities. E.g., some Consumer's Existing Payment Software may refuse the disclosure of specific payment instruments at brand selection time and may delay this selection to the "Check Payment Possibility" invocation using its own user interface.

The IOTP Payment Bridge's capabilities do not only deal with actual payments between the Consumer and the Payment Handler but extend to the following:

o translation and (dis)assemblage of messages between the formats of

  the IOTP Payment API and those of the Existing Payment Software.
  Payment API requests and response are strictly 1-to-1 related.

o Consumer's payment instrument selection by the means of an

  unsecured/public export of the relationship of payment brands,
  payment protocols, and payment instruments (identifiers).
  Generally, this includes not just the brand (Mondex, GeldKarte,
  etc.) but also which specific instance of the instrument and
  currency to use (e.g., which specific Mondex card and which
  currency of all those available).

However, some Existing Payment Software may defer the selection of the payment instrument to the actual payment carrying-out or it may even lack any management of payment instruments. E.g., chip card based payment methods may offer - Point of Sale like - implicit selection of the payment instrument by simple insertion of the chip card into the chip card reader or it interrogates the inserted card and requests an acknowledge (or selection) of the detected payment instrument(s).

o payment progress checks, e.g., is there enough funds available to

  carry out the purchase, or enough funds left for the refund,

o IOTP Payment Receipt checks which might be performed over its

  Packaged Content or by other means.

o recoding of payment scheme specific receipts into a format which

  can be displayed to the user or printed,

o cancellation of payment, even though it is not complete,

o suspension and resumption of payment transactions. Two kinds of

  failures the Existing Payment Software might deal with are (1) the
  time-out of the network connection and (2) lack of funds.  For
  resolution, the IOTP Application Core may try the suspension with
  a view to later possible resumption.

o recording the payment progress and status on a database. E.g.,

  information about pending payments might be used to assist their
  continuation when the next payment protocol message is received.

o payment transaction status inquiry, so that the inquirer - IOTP

  Application Core or User - can determine the appropriate next
  step.

o balance inquiry or transaction history, e.g., consumers may

  interrogate their chip card based payment instrument or remotely
  administer some account in advance of a payment transaction
  acknowledge,

o inquiry on abnormal interrupted payment transactions, which might

  be used by the IOTP Application Core to resolve these pending
  transactions at startup (after power failure).

o payment progress indication. This could be used to inform the end

  user of details on what is happening with the payment.

o payment method specific authentication methods.

Existing Payment Software may not provide full support of these capabilities. E.g., some payment schemes may not support or may even prevent the explicit transaction cancellation at arbitrary phases of the payment process. In this case, the IOTP Payment Bridge has to implement at least skeletons that signal such lack of support by the use of specific error codes (see below).

The Existing Payment Software's capabilities vary extremely. It

o supports payment scheme specific processing, supervision,

  validation, and error resolution.  It is expected, that many
  errors are tried to be resolved first by the extended exchange of
  Payment Exchange messages.

o provides hints for out-of-band failure resolution on failed

  inbound resolution - inbound resolution is invisible to the IOTP
  Application Core.

o may implement arbitrary transaction data management and inquiry

  mechanisms ranging from no transaction recording, last transaction
  recording, chip card deferred transaction recording, simple
  transaction history to sophisticated persistent data management
  with flexible user inquiry capabilities.  The latter is required
  by Payment Handlers for easy and cost effective failure
  resolution.

o implements the payment scheme specific dialog boxes.

Even the generic dialog boxes of the IOTP Application Core might be unsuitable: Particular (business or scheme) rules may require some dedicated appearance / structure / content or the dialog boxes, may prohibit the unsecured export of payment instruments, or may prescribe the pass phrase input under its own control.

Message Flow

The following lists all functions of the IOTP Payment API:

  o  Brand Compilation Related API Functions

"Find Accepted Payment Brand" identifies the accepted payment brands for any indicated currency amount.

"Find Accepted Payment Protocol" identifies the accepted payment protocols for any indicated currency amount (and brand) and returns payment scheme specific packaged content for brand selection purposes.

This function might be used in conjunction with the aforementioned function or called without any brand identifier.

"Get Payment Initialization Data" returns additional payment scheme specific packaged content for payment processing by the payment handler.

"Inquire Authentication Challenge" returns the payment scheme specific authentication challenge value.

"Check Authentication Response" verifies the returned payment scheme specific authentication response value.

"Change Process State" is used (here only) for abnormal termination. (cf. Payment Processing Related API Functions).

  o  Brand Selection Related API Functions

"Find Payment Instrument" identifies which instances of a payment instrument of a particular payment brand are available for use in a payment.

"Check Payment Possibility" checks whether a specific payment instrument is able to perform a payment.

"Authenticate" forwards any payment scheme specific authentication data to the IOTP Payment Bridge for processing.

"Change Process State" is used (here only) for abnormal termination. (cf. Payment Processing Related API Functions).

  o  Payment Processing Related API Functions

"Start or Resume Payment Consumer/Payment Handler" initiate or resume a payment transaction. There exist specific API functions for the two trading roles Consumer and Payment Handler.

"Continue Process" forwards payment scheme specific data to the Existing Payment Software and returns more payment scheme specific data for transmission to the counter party.

"Change Process State" changes the current status of payment transactions. Typically, this call is used for termination or suspension without success.

  o  General Inquiry API Functions

"Remove Payment Log" notifies the IOTP Payment Bridge that a particular entry has been removed from the Payment Log of the IOTP Application Core.

"Payment Instrument Inquiry" retrieves the properties of Payment Instruments.

"Inquire Pending Payment" reports any abnormal interrupted payment transaction known by the IOTP Payment Bridge.

Payment Processing Related Inquiry API Functions

"Check Payment Receipt" checks the consistency and validity of IOTP Payment Receipts, received from the Payment Handler or returned by "Inquire Process State" API calls. Typically, this function is called by the Consumer during the final processing of payment transactions. Nevertheless, this check might be advantageous both for Consumers and Payment Handlers on failure resolution.

"Expand Payment Receipt" expands the Packaged Content of IOTP Payment Receipts as well as payment scheme specific payment receipts into a form which can be used for display or printing purposes.

"Inquire Process State" responds with the payment state and the IOTP Payment Receipt Component. Normally, this function is called by the Payment Handler for final processing of the payment transaction.

"Start Payment Inquiry" prepares the remote inquiry of the payment transaction status and responds with payment scheme specific data that might be needed by the Payment Handler for the Consumer initiated inquiry processing.

"Inquire Payment Status" is called by the Payment Handler on Consumer initiated inquiry requests. This function returns the payment scheme specific content of the Inquiry Response Block.

"Continue Process" and "Change Process State" (cf. Payment Processing Related API Calls)

  o  Other API Functions

"Manage Payment Software" enables the immediate activation of the Existing Payment Software. Further user input is under control of the Existing Payment Software.

"Call Back" provides a general interface for the visualization of transaction progress by the IOTP Application Core.

The following table shows which API functions must (+), should (#), or might (?) be implemented by which Trading Roles.

API function Consumer Payment Handler Merchant


-------- --------------- --------

Find Accepted Payment Brand + Find Accepted Payment Protocol # Find Payment Instrument +

Get Payment Initialization Data + Check Payment Possibility +

Start Payment Consumer + Start Payment Payment Handler + Resume Payment Consumer # Resume Payment Payment Handler #

Continue Process + + Inquire Process State + + ? Change Process State + + ? Check Payment Receipt + ? Expand Payment Receipt # ?

Remove Payment Log ? ? ?

Inquire Authentication Challenge ?

Authenticate + Check Authentication Response ?

Payment Instrument Inquiry ? Inquire Pending Payment # # Start Payment Inquiry ? Inquire Payment Status ?

Manage Payment Software # ? ?

Call Back #

    Table 1: Requirements on API Functions by the Trading Roles

The next sections sketch the relationships and the dependencies between the API functions. They provide the informal description of the progress alternatives and depict the communication and synchronization between the general IOTP Application Core and the payment scheme specific modules.

Authentication Documentation Exchange

This section describes how the functions in this document are used together to process authentication.

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Authenticator Inquire Authentication Challenge(Alg1*) -> IPB

               Inq. Auth. Challenge Response(Alg1,Ch1)   <- IPB
               . . .
               Inquire Authentication Challenge(Algn*)   -> IPB
               Inq. Auth. Challenge Response(Algn,Chn)   <- IPB
               Create and transmit Authentication Request Block

Authenticatee Authenticate(Alg1, Ch1) -> IPB

               AuthenticateResponse(...)                 <- IPB
               . . .
               Authenticate(Algm, Chm)                   -> IPB
               AuthenticateResponse(Res)                 <- IPB
               Create and transmit Authentication Response Block

Authenticator Check Authentication Response(Algm,Chm,Res)->IPB

               Check Auth. Response()                     <-IPB
               Create and transmit Authentication Status Block
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
              Figure 2. Authentication Message Flows

1. (Authenticator Process) None, one or multiple IOTP Payment Bridges

  (IPB) are requested for one or multiple authentication challenge
  values ("Inquire Authentication Challenge").  Each value is
  encapsulated in an IOTP Authentication Request Component.  In
  addition, the IOTP Application Core may add payment scheme
  independent authentication methods.  All of them form the final
  IOTP Authentication Request Block, which describes the set of
  authentication methods being supported by the authenticator and
  from which the Authenticatee has to choose one method.
  Note that the interface of the API function is limited to the
  response of exactly one algorithm per call.  If the IOTP
  Application Core provides a choice of algorithms for input, this
  choice should be reduced successively by the returned algorithm
  ({Alg(i+1)*} is subset of {Algi*}).
  During the registration of new Payment Instruments, the IOTP
  Payment Bridge notifies the IOTP Application Core about the
  supported authentication algorithms.

2. On the presence of an IOTP Authentication Block within the

  received IOTP message, the Authenticatee's IOTP Application Core
  checks whether the IOTP transaction type in the current phase
  actually supports the authentication process.
  For each provided Authentication Request Component, the IOTP
  Application Core analyzes the algorithms' names, the transaction
  context, and optionally user preferences in order to determine the
  system components which are capable to process the authentication
  request items.  Such system components might be the IOTP
  Application Core itself or any of the registered IOTP Payment
  Bridges.
  Subsequently, the IOTP Application Core requests the responses to
  the supplied challenges from the determined system components in
  any order.  The authentication trials stop with the first
  successful response, which is included in the IOTP Authentication
  Response Block.
  Alternatively, the IOTP Application might ask for a user
  selection.  This might be appropriate, if two or more
  authentication algorithms are received that require explicit user
  interaction, like PIN or chip card insertion.
  The Authenticatee's organizational data is requested by an IOTP
  Authentication Request Block without any content element.  On
  failure, the authentication (sequence) might be retried, or the
  whole transaction might be suspended or cancelled.

3. (Authenticator Process) The IOTP Application Core checks the

  presence of the IOTP Authentication Response Component in the
  Authentication Response Block and forwards its content to the
  generator of the associated authentication challenge for
  verification ("Check Authentication Response").
  On sole organizational data request, its presence is checked.
  Any verification must succeed in order to proceed with the
  transaction.

Brand Compilation

The following shows how the API functions are used together so that the Merchant can (1) compile the Brand List Component, (2) generate the Payment Component, and (3) adjust the Order Component with payment scheme specific packaged content.

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Merchant For each registered IOTP Payment Bridge

             |  Find Accepted Payment Brand()             -> IPB
             |  Find Accepted Payment Brand Response (B*) <- IPB
             |  Find Accepted Payment Protocol(B1)        -> IPB
             |  Find Accepted Payment Protocol Res.(P1*)  <- IPB
             |  . . .
             |  Find Accepted Payment Protocol(Bn)        -> IPB
             |  Find Accepted Payment Protocol Res.(Pn*)  <- IPB
             Create one Brand List Component, ideally sharing
               common Brand, Protocol Amount, Currency Amount,
               and Pay Protocol Elements
             Create Trading Protocol Options Block
             On brand independent transactions
             |  Create Brand Selection Component, implicitly
             |  Get Payment Initialization Data(B1,P1)   -> IPB
             |  Get Payment Initialization Data Res.()   <- IPB
             |  Optionally
             |  |  Inquire Process State()               -> IPB
             |  |  Inquire Process State Response(State) <- IPB
             |  Create Offer Response Block
             Transmit newly created Block(s)

Consumer Consumer selects Brand (Bi)/Currency/Protocol (Pj)

               from those that will work and generates Brand
               Selection Component - at least logically
             On brand dependent transaction
             |  Transmit Brand Selection Component

Merchant On brand dependent transaction

             |  Get Payment Initialization Data(Bi,Pj)   -> IPB
             |  Get Payment Initialization Data Res.()   <- IPB
             |  Optionally
             |  |  Inquire Process State()               -> IPB
             |  |  Inquire Process State Response(State) <- IPB
             |  Create Offer Response Block
             |  Transmit newly created Block
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
             Figure 3. Brand Compilation Message Flows

1. The Merchant's commerce server controls the shopping dialog with

   its own mechanisms until the Consumer checks out the shopping
   cart and indicates the payment intention.  The notion shopping
   subsumes any non-IOTP based visit of the Merchant Trading Role's
   (which subsumes Financial Institutes) web site in order to
   negotiate the content of the IOTP Order Component.  The
   subsequent processing switches to the IOTP based form by the
   activation of the Merchant's IOTP aware application.

2. The IOTP Application Core inquires for the IOTP level trading

   parameters (Consumer's shopping identifier, payment direction,
   initial currency amounts, discount rates, Merchant's and Delivery
   Handler's Net Locations, Non-Payment Handler's Organizational

3. The registered IOTP Payment Bridges are inquired by the IOTP

   Application Core about the accepted payment brands ("Find
   Accepted Payment Brand").  Their responses provide most of the
   attribute values for the compilation of the Brand List
   Component's Brand Elements.  The IOTP Application Core might
   optionally match the returned payment brands with Merchant's
   general preferences.
   The IOTP Application Core must provide any wallet identifiers, if
   they are required by the IOTP Payment Bridges which signal their
   need by specific error codes (see below).  Any signaled error
   that could not be immediately solved by the IOTP Application Core
   should be logged - this applies also to the subsequent API calls
   of this section.  In this case, the IOTP Application Core creates
   an IOTP Error Block (hard error), transmits it to the Consumer,
   and terminates the current transaction.

4. The IOTP Application Core interrogates the IOTP Payment Bridges

   for each accepted payment brand about the supported payment
   protocols ("Find Accepted Payment Protocol").  These responses
   provide the remaining attribute values of the Brand Elements as
   well as all attribute values for the compilation of the Brand
   List Component's Protocol Amount and Pay Protocol Elements.
   Furthermore, the organisational data about the Payment Handler is
   returned.  The IOTP Application Core might optionally match the
   returned payment brands with Merchant's general preferences.
   Alternatively, the IOTP Application Core might skip the calls of
   "Find Accepted Payment Brands" (cf. Step 3) and issue the "Find
   Accepted Payment Protocol" call without any Brand given on the
   input parameter list.  In this case, the IOTP Payment Bridge
   responds to the latter call with the whole set of payment schemes
   supported w.r.t. the other input parameters.

5. The steps 3 and 4 are repeated during IOTP Value Exchange

   transactions - these steps are omitted in the previous figure.

6. The IOTP Application Core compiles the Brand List Component(s)

   and the IOTP Trading Protocol Options Block.  It is recommended
   that the "equal" items returned by IOTP Payment Bridge function
   calls are shared due to the extensive linking capabilities within
   the Brand List Component.  However, the compilation must consider
   several aspects in order to prevent conflicts - sharing detection
   might be textual matching (after normalization):
  o  Packaged Content Elements contained in the Brand List Component
     (and subsequently generated Payment and Order Components) might
     be payment scheme specific and might depend on each other.
  o  Currently, IOTP lacks precise rules for the content of the
     Packaged Content Element.  Therefore, transaction / brand /
     protocol / currency amount (in)dependent data might share the
     same Packaged Content Element or might spread across multiple
     Packaged Content Elements.
  o  The Consumer's IOTP Application Core transparently passes the
     Packaged Content Elements to the IOTP Payment Bridges which
     might not be able to handle payment scheme data of other
     payment schemes, accurately.
   The rules and mechanisms of how this could be accomplished are
   out of the scope of this document.  Furthermore, this document
   does not define any further restriction to the IOTP
   specification.

7. The IOTP Application Core determines whether the IOTP message can

   be enriched with an Offer Response Block.  This is valid under
   the following conditions:
  o  All payment alternatives share the attribute values and
     Packaged Content Elements of the subsequently generated IOTP
     Payment and Order Components.
  o  The subsequently generated data does not depend on any IOTP
     BrandSelInfo Elements that might be reported by the consumer
     within the TPO Selection Block in the brand dependent variant.
   If both conditions are fulfilled, the IOTP Application Core might
   request the remaining payment scheme specific payment
   initialization data from the IOTP Payment Bridge ("Get Payment
   Initialization Data") and compile the IOTP Offer Response Block.
   Optionally, the IOTP Application Core might request the current
   process state from the IOTP Payment Bridge and add the inferred
   order status to the IOTP Offer Response Block.  Alternatively,
   IOTP Application might determine the order status on its own.
   As in step 6, the rules and mechanisms of how this could be
   accomplished are out of the scope of this document.

8. The IOTP Application Core compiles the IOTP TPO Message including

   all compiled IOTP Blocks and transmits the message to the
   Consumer.  The IOTP Application Core terminates if an IOTP Offer
   Response Block has been created.

9. The Consumer performs the Brand Selection Steps (cf. Section 2.3)

   and responds with a TPO Selection Block if no IOTP Offer Response
   Block has been received.  Otherwise, the following step is
   skipped.

10. On brand dependent transactions, the IOTP Application Core

   requests the remaining payment scheme specific payment
   initialization data from the IOTP Payment Bridge ("Get Payment
   Initialization Data"), compiles the IOTP Offer Response Block,
   transmits it to the Consumer, and terminates.  Like Step 7, the
   IOTP Application Core might access the current process state of
   the IOTP Payment Bridge for the compilation of the order status.

Any error during this process raises an IOTP Error Block.

Brand Selection

This section describes the steps that happen mainly after the Merchant's Brand Compilation (in a brand independent transaction). However, these steps might partially interlace the previous process (in a brand dependent transaction).

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Merchant Merchant generates Brand List(s) containing

               Brands, Payment Protocols and Currency Amounts
             On brand independent transactions
             |  Merchant generates Offer Response Block

Consumer Compile set(s) of Brands B/Protocols P

             for each set
             |  Find Payment Instrument(B, P, C)        -> IPB
             |  Find Payment Instrument Response (PI*)    <- IPB
             Consumer selects Brand/Currency/Payment Instrument
               from those that will work and generates Brand
               Selection Component
             For the Selection
             |  Get Payment Initialization Data(B,C,PI,P) -> IPB
             |  Get Payment Initialization Data Response()<- IPB
             On brand dependent transaction
             |  Generate and transmit TPO Selection Block

Merchant On brand dependent transaction

             |  Merchant checks Brand Selection and generates
             |  and transmits Offer Response Block
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
              Figure 4. Brand Selection Message Flows

1. The Merchant's commerce server controls the shopping dialog with

  its own mechanisms until the Consumer checks out the shopping cart
  and indicates his payment intention.  The subsequent processing
  switches to the IOTP based form by the activation of the
  Merchant's IOTP aware application.

2. The IOTP Application Core compiles the IOTP Trading Protocol

  Options Block which contains the IOTP Brand List Component(s)
  enumerating Merchant's accepted payment brands and payment
  protocols and initiates the Brand Selection process.

3. This first IOTP message activates the Consumer's IOTP aware

  application, e.g., the Web browser invokes a helper application
  (e.g., Java applet or external application).  Its IOTP Application
  Core
  o  infers the accepted payment brands, payment protocols, payment
     direction, currencies, payment amounts, any descriptions etc.,
     and their relationships from the IOTP message,
  o  determines the registered IOTP Payment Bridges,
  o  compiles one or multiple sets of brand and protocol such that
     the join of all sets describes exactly the payment alternatives
     being offered by the Merchant.
  o  inquires payment (protocol) support and the known payment
     instruments from each registered IOTP Payment Bridge for each
     compiled set ("Find Payment Instrument").  However, some IOTP
     Payment Bridges may refuse payment instrument distinction.
  The payment protocol support may differ between payment
  instruments if the IOTP Payment Bridge supports payment instrument
  distinction.
  These API calls are used to infer the payment alternatives at the
  startup of any payment transaction (without user unfriendly
  explicit user interaction).
  The IOTP Application Core must provide wallet identifiers, if they
  are requested by the IOTP Payment Bridges which signal their need
  by specific error codes (see below).
  It is recommended that the IOTP Application Core manages wallet
  identifiers.  But for security reasons, it should store pass
  phrases in plain text only in runtime memory.  Developers of IOTP
  Payment Bridges and payment software modules should provide a thin
  and fast implementation - without lengthy initialization processes
  - for this initial inquiry step.

4. The IOTP Application Core verifies the Consumer's payment

  capabilities with the Merchant's accepted payment brands and
  currencies,
  o  displays the valid payment instruments and payment instrument
     independent payment brands (brand and protocol) together with
     their purchase parameters (payment direction, currency,
     amount), and
  o  requests the Consumer's choice or derives it automatically from
     any configured preferences.  Any selection ties one IOTP
     Payment Bridge with the following payment transaction.
  The handling and resolution of unavailable IOTP Payment Bridges
  during the inquiry in Step 3 is up to the IOTP Application Core.
  It may skip these IOTP Payment Bridges or may allow user supported
  resolution.
  Furthermore, it may offer the registration of new payment
  instruments when the Consumer is asked for payment instrument
  selection.

5. The IOTP Application Core interrogates the fixed IOTP Payment

  Bridge whether the payment might complete with success ("Check
  Payment Possibility").  At this step, the IOTP Payment Bridge may
  issue several signals, e.g.,
  o  payment can proceed immediately,
  o  required peripheral inclusive of some required physical payment
     instrument (chip card) is unavailable,
  o  (non-IOTP) remote party (e.g., issuer, server wallet) is not
     available,
  o  wallet identifier or pass phrase is required,
  o  expired payment instrument (or certificate), insufficient
     funds, or
  o  physical payment instrument unreadable.
  In any erroneous case, the user should be notified and offered
  accurate alternatives.  Most probably, the user might be offered
  o  to resolve the problem, e.g., to insert another payment
     instrument or to verify the periphery,
  o  to proceed (assuming its success),
  o  to cancel the whole transaction, or
  o  to suspend the transaction, e.g., initiating a nested
     transaction for uploading an electronic purse.
  If the payment software implements payment instrument selection on
  its own, it may request the Consumer's choice at this step.
  If the check succeeds, it returns several IOTP Brand Selection
  Info Elements.

6. The Steps 2 to 5 are repeated and possibly interlaced for the

  selection of the second payment instrument during IOTP Value
  Exchange transactions - this is omitted in the figure above.

7. The IOTP Brand Selection Component is generated and enriched with

  the Brand Selection Info elements.  This component is transmitted
  to the Merchant inside a TPO Selection Block if the received IOTP
  message lacks the IOTP Offer Response Block.  The Merchant will
  then respond with an IOTP Offer Response Block (following the
  aforementioned compilation rules).

Successful Payment

An example of how the functions in this document are used together to effect a successful payment is illustrated in the Figure 5. In the figure 5, PS0, PS1, ..., and PSn indicate the nth PayScheme Packaged Content data, and [ ] indicates optional.

(Technically, two payments happen during IOTP Value Exchange transactions.)

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Consumer Start Payment Consumer(Amount,[PS0]...) -> IPB

               Start Payment Cons. Res.([PS1], CS=Cont.)  <- IPB
               Create and transmit Payment Request Block

Payment Handler Start Payment Pay. Handler(Amount, [PS1]) -> IPB

               Start Payment PH Response(PS2, CS=Cont.)   <- IPB
               Create and transmit Payment Exchange Block

Consumer Continue Process(PS2) -> IPB

               Continue Process Response(PS3, CS=Cont.)   <- IPB
        ... CONTINUE SWAPPING PAYMENT EXCHANGES UNTIL ...

Payment Handler Continue Process Response([PSn], CS=End) <- IPB

               Request any local payment receipt
               |  Inquire Process State()                 -> IPB
               |  Inquire Proc. State Resp.(State, [Rcp.])<- IPB
               Create and transmit Payment Response Block
               Terminate transaction, actively
               |  Change Process State(State)             -> IPB
               |  Change PS Response(State=CompletedOK)   <- IPB

Consumer On receipt of final payment scheme data

               |  Continue Process(PSn)                   -> IPB
               |  Continue Process Response(CS=End)       <- IPB
               Check Payment Receipt(Receipt)             -> IPB
               Check Payment Receipt Response()           <- IPB
               Request any local payment receipt
               |  Inquire Process State()                 -> IPB
               |  Inquire Proc. State Resp.(State, [Rcp.])<- IPB
               Terminate transaction, actively
               |  Change Process State(State)             -> IPB
               |  Change PS Response(State=CompletedOk)   <- IPB
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
              Figure 5. Example Payment Message Flows

1. After Brand Selection and receipt of the IOTP Offer Response

  Block, the Consumer switches from communicating with the Merchant
  to communicating with the Payment Handler.
  This might be a milestone requiring the renewed Consumer's
  agreement about the payment transaction's continuation.
  Particularly, this is a good moment for payment suspension (and
  even cancellation), which will be most probably supported by all
  payment schemes.  Simply, because the actual payment legacy
  systems have not yet been involved in the current transaction.
  Such an agreement might be explicit per transaction or automatic
  based on configured preferences, e.g., early acknowledgments for
  specific payment limits.
  It is assumed, that the transaction proceeds with minimal user
  (Consumer and Payment Handler) interaction and that its progress
  is controlled by the IOTP Application Core and IOTP Payment
  Bridge.

2. In order to open the actual payment transaction, the IOTP

  Application Core issues the "Start Payment Consumer" request
  towards the IOTP Payment Bridge.  This request carries the whole
  initialization data of the payment transaction being referred to
  by the IOTP Payment Bridge for subsequent consistency checks:
  o  payment brand and its description from the selected Brand
     Element of the IOTP Brand List Component,
  o  payment instrument from preceding inquiry step,
  o  further payment parameters (currency, amount, direction,
     expiration) from the selected Currency Amount element, Brand
     List Component, and Payment Component of the IOTP Offer
     Response Block,
  o  payment protocol from the selected IOTP Pay Protocol Element,
  o  order details contained in the IOTP Order Component which might
     be payment scheme specific,
  o  payment scheme specific data inclusive of the payment protocol
     descriptions from the IOTP Protocol Amount Element, and IOTP
     Pay Protocol Element, and
  o  payment scheme specific data inclusive of the payment protocol
     descriptions, in which the name attribute includes the prefix
     as "Payment:" from the Trading Role Data Component.
  Generally, the called API function re-does most checks of the
  "Check Payment Possibility" call due to lack of strong
  dependencies between both requests: There might be a significant
  delay between both API requests.
  The called API function may return further payment scheme specific
  data being considered as payment specific initialization data for
  the Payment Handler's IOTP Payment Bridge.
  If the fixed Existing Payment Software implements payment
  instrument selection on its own, it may request the Consumer's
  choice at this step.
  The IOTP Payment Bridge reports lack of capability quite similarly
  to the "Check Payment Possibility" request to the IOTP Application
  Core.  The Consumer may decide to resolve the problem, to suspend,
  or to cancel the transaction, but this function call must succeed
  in order to proceed with the transaction.
  Developers of payment modules may decide to omit payment
  instrument related checks like expiration date or refunds
  sufficiency, if such checks are part of the specific payment
  protocol.
  If the IOTP Payment Bridge requests wallet identifiers or pass
  phrases anywhere during the payment process, they should be
  requested by this API function, too.  It is recommended that the
  IOTP Application Core stores plain text pass phrases only in
  runtime memory.
  Finally, the IOTP Application Core generates the IOTP Payment
  Request Block, inserts any returned payment scheme data, and
  submits it to the Payment Handler's system.

3. The Payment Handler's IOTP Application Core opens the payment

  transaction calling the "Start Payment Payment Handler" API
  function.  The payment brand, its description, payment protocol,
  payment specific data, payment direction, currency and payment
  amount are determined quite similar to the Consumer's IOTP
  Application Core.  Furthermore, the content of the IOTP Payment
  Scheme Component and the IOTP Brand Selection Info Elements are
  passed to this function.
  On success, the Payment Handler's IOTP Payment Bridge responds
  with payment scheme specific data.  On failures, this non-
  interactive server application has to resolve any problems on its
  own or to give up aborting the payment transaction.  However, the
  Consumer may restart the whole payment transaction.  Anyway, the
  payment log file should reflect any trials of payments.
  Eventually, the Payment Handler informs the Consumer about the
  current IOTP Process State using the IOTP Payment Response or IOTP
  Error Block.
  Note that the "Start Payment Payment Handler" call might return
  the Continuation Status "End" such that payment processing
  proceeds with Step 7.

4. The IOTP Application Core verifies the presence of the Payment

  Exchange Block in the IOTP message and passes the contained
  payment scheme specific data to the fixed IOTP Payment Bridge
  ("Continue Process") which returns the next IOTP Payment Scheme
  Component.
  This Payment Scheme Component is encapsulated in an IOTP Payment
  Exchange Block and transmitted to the Payment Handler.

5. The Payment Handler's IOTP Application Core verifies the presence

  of the Payment Exchange Block and passes the contained payment
  scheme specific data to the fixed IOTP Payment Bridge ("Continue
  Process") which returns the next IOTP Payment Scheme Component for
  encapsulation and transmission to the Consumer.

6. The payment process continues with IOTP Payment Exchange Block

  exchanges, carrying the payment scheme specific data.  Each party
  (1) submits the embedded payment scheme specific data
  transparently to the appropriate IOTP Payment Bridge calling the
  "Continue Process" API function, (2) wraps the returned payment
  scheme specific data into an IOTP Payment Exchange Block, and (3)
  transmits this block to the counter party.
  However, the processing of the payment scheme specific data may
  fail for several reasons.  These are signaled by specific error
  codes which are transformed to IOTP Payment Response Blocks
  (generated by Payment Handler) or IOTP Error Blocks (both parties
  may generate them) and transmitted to the counter party.

7. Eventually, the Payment Handler's IOTP Payment Bridge recognizes

  the termination of the payment transaction and reports this by the
  continuation status "End" on the output parameter of "Continue
  Process" (or "Start Payment Payment Handler").  Then, the IOTP
  Application Core issues the "Inquire Process State" API call and
  verifies whether an IOTP Payment Receipt Component has been
  returned.  The IOTP Application Core wraps the payment receipt,
  the status response, and the optional payment scheme specific data
  in an IOTP Payment Response Block and transmits this block to the
  Consumer.
  However, any of these API calls may fail or any response might be
  incomplete (e.g., lack of payment receipt).  Then, the Consumer
  has to be notified about the failed processing by an IOTP Error
  Block.
  Finally, the Payment Handler terminates the payment transaction
  with the "Change Process State" API call without awaiting any
  further response from the Consumer.  Further failures are not
  reported to the Consumer.
  Note that it might be possible that the Consumer's IOTP Payment
  Bridge has returned the previous payment scheme specific data with
  the continuation status "End".  Even in the absence of this
  knowledge - this status is not exchanged between the Consumer and
  the Payment Handler - the Payment Handler must not supply any
  further payment scheme specific data.  Such data will be rejected
  by the Consumer's IOTP Payment Bridge.

8. The Consumer passes the optional payment scheme specific data and

  the payment receipt to the fixed IOTP Payment Bridge by "Continue
  Process" and "Check Payment Receipt" API calls.
  Afterwards, the IOTP Application Core issues the "Inquire Process
  State" API call and verifies whether extensions to the payment
  receipt have been returned.
  Finally, the transaction is terminated by calling the "Change
  Process State" API function which verifies and synchronizes the
  reported payment status with the local one and signals any
  inconsistencies.  Any Inconsistency and returned status text
  should be displayed to the Consumer.
  At this point, the payment transaction has already been closed by
  the Payment Handler.  Therefore, any failure has to be resolved
  locally or out-of-band.

Payment Inquiry

In Baseline IOTP, Payment inquiries are initiated by the Consumer in order to verify the current payment progress and process state at the remote Payment Handler. In the figure 6, PS1 and PS2 indicate the first and second PayScheme Packaged Content data, and [ ] indicates optional.

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Consumer Start Payment Inquiry() -> IPB

               Start Payment Inquiry Response([PS1])      <- IPB
               Create and transmit Inquiry Request Trading Block

Payment Handler Inquire Payment Status([PS1]) -> IPB

               Inquire Payment Status Res.(State, [PS2])  -> IPB
               Create and transmit Inquiry Response Trading
                 Block

Consumer If Payment Scheme Data present

               |  Continue Process(PS2)                   -> IPB
               |  Continue Process Response(CS=End)       <- IPB
               Change Process State(State)                -> IPB
               Change Process State Response(State)       <- IPB
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
              Figure 6. Remote Process State Inquiry

1. The Consumer might initiate a payment inquiry once the payment

  transaction has been opened by the IOTP Application Core, i.e., at
  any time after the initial submission of the IOTP Payment Request
  Block.  The IOTP Application Core requests any additional specific
  payment scheme data from the IOTP Payment Bridge which has been
  fixed during brand selection (cf. Section 2.3) using the "Start
  Payment Inquiry" API request.
  Erroneous API responses should be reported to the Consumer and
  valid alternatives (typically retry and cancellation) should be
  presented by the IOTP Application Core.
  This request might perform the complete initialization, e.g.,
  availability check of periphery or pass phrase supplement, and the
  IOTP Payment Bridge reports lack of capability quite similarly to
  the "Check Payment Possibility" request to the IOTP Application
  Core.
  If the IOTP Payment Bridge requests wallet identifiers or pass
  phrases anywhere during the payment process, they should be
  requested by this API function, too.  It is recommended that the
  IOTP Application Core store plain text pass phrases only in
  runtime memory.
  The IOTP Application Core encapsulates any Payment Scheme
  Component in an IOTP Inquiry Request Block and submits the block
  to the Payment Handler.

2. The Payment Handler analyses the IOTP Inquire Request Block, maps

  the Transaction Identifier to payment related attributes (brand,
  consumer and payment identifiers), determines the appropriate IOTP
  Payment Bridge, and forwards the request to the this IOTP Payment
  Bridge ("Inquire Payment Status").  The IOTP Application Core
  transforms the response to an IOTP Inquiry Response Block and
  transmits it to the Consumer.

3. On receipt of the respective IOTP Inquiry Response Block the

  Consumer's IOTP Application Core submits any encapsulated payment
  scheme specific data to the IOTP Payment Bridge for verification
  ("Continue Process").

4. The IOTP Application Core passes the reported payment status

  (except textual descriptions) to the IOTP Payment Bridge ("Change
  Process State") for verification purposes and payment status
  change.  The IOTP Payment Bridge reports any inconsistencies as
  well as the final payment status to the IOTP Application Core.
  Any additional information that might be of interest to the
  Consumer has to be displayed by the IOTP Payment Bridge or
  Existing Payment Software on their own.

Abnormal Transaction Processing

Failures and Cancellations

The IOTP specification distinguishes between several classes of failures:

  o  Business and technical errors
  o  Error depths of transport, message and block level
  o  Transient errors, warnings, and hard errors.

Any IOTP Payment API has to deal with the receipt of failure notifications by and failure responses. This proposal has borrowed the basic mechanisms for error reporting between the IOTP Application Core and the IOTP Payment Bridge from the actual protocol: Business

errors are reported by Status Components within IOTP Response Blocks while technical errors are signaled by Error Components within IOTP Error Blocks.

Cancellations are mimicked as specific business errors which might be initiated by each trading party.

Preferring slim interfaces, this IOTP Payment API introduces one additional Error Code value for business error indication - errors can be raised on every API call. On receipt of this value, the IOTP Application Core has to infer further details by the issuance of the API function call "Inquire Process State".

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Any Party Issue some API request -> IPB

               Error Response(Error Code)                 <- IPB
               On "Business Error" response
               |  Inquire Process State()                 -> IPB
               |  Inquire P.S. Resp.(State, Receipt)      <- IPB
               Analyze local process state and try to resolve
                  with optional user interaction
               If Process State Change needed
               |  Change Process State (State)            -> IPB
               |  Change Process State Response(State)    <- IPB
               If counter party's notification required
               |  Create Error or Cancel Block (, add to next
               |  message, ) and transmit it to counter party
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
                Figure 7.  Error Response from IPB

The specific Completion Codes "ConsCancelled", "MerchCancelled", and "PaymCancelled" - returned by "Inquire Process State" - determine that the IOTP Cancel Block has to be created instead of an IOTP Error Block.

The rules for determining the required behavior of the IOTP Application Core are given in the IOTP specification.

Note that any payment (intermediate) termination, i.e., failures, cancellations, and even successes are always reported to the IOTP Payment Bridge by the API function "Change Process State". This API function does both status changes and consistency checking / synchronization. Any suspicion of inconsistency should be reported by the IOTP Payment Bridge for display by the IOTP Application Core.

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*

Any Party Error Block or Cancel Block Received

               If Change Process State required
               |  Change Process State (State)            -> IPB
               |  Change Process State Response(State)    <- IPB
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
         Figure 8.  Error Notification from counter party

Not every failure might be visible at the IOTP layer, e.g., the processing of payment transactions might temporarily be hampered by intermediate failures at the payment scheme or protocol transport layer which might be resolved by the actual components.

However, final failures or cancellations have to be reported at the IOTP layer. E.g., communication time-outs and heavily faulty communication channels may disable the transaction.

Any system component may implement time-out recognition and use the aforementioned API mechanisms for the notification of process state changes. But, time-outs may happens while communicating with both the counter party and local system components, like chip card readers or IOTP Payment Bridges. Anyway, the Consumer's IOTP Application Core should notify the Consumer about the resolution alternatives, i.e., retry, suspension, and cancellation.

Resumption

Payment transaction resumption may apply at different steps of a payment transaction:

o The Consumer's and Payment Handler's view of the transaction might

  not be synchronized: Due to different time-out values the payment
  transaction may not have been suspended by the counter party.
  Any "Resume Payment ..." API function responds with an Error Code
  on non-suspended payment transaction that signals a business
  error.  Afterwards the IOTP Application Core has to issue the
  "Inquire Process State" API call for further analysis of the
  process state.

o One IOTP message sent by one party might not be processed

  successfully or even received by the counter party.  This needs to
  be handled by the actual payment scheme.  It is expected that the
  IOTP Application Core will not recognize anything.

o IOTP does not provide any specific signal for payment resumption.

  On receipt of every IOTP Payment Exchange Block, the IOTP
  Application Core has to decide whether this Block belongs to a
  pending transaction or to a suspended transaction that should be
  resumed.  The IOTP Application Core might call the "Inquire
  Process State" API function to update any lack of knowledge.
  Any "Resume Payment" API function responds with an Error Code on
  non-suspended payment transaction that signals a business error.
  Similar, the "Continue Process" API function should report
  business errors on non-pending payment transactions.

o The payment transaction may not have been created at the Payment

  Handler (early suspension and failed data transmission).  In that
  case, the IOTP Application Core should respond with a business
  error that signals the repetition of the payment transaction (by
  the Consumer).
  Any "Resume Payment", "Continue Process" or "Inquire Process
  State" API function should return with an Error Code
  "AttValIllegal" on non-existent payment transaction whereby the
  further Error Attribute "Names" denote the payment identifier.

o The IOTP Application Core should always request fresh payment

  scheme specific data on resumption - for synchronization purposes
  with the Existing Payment Software.  Old data in the cache that
  has not been sent to the counter party should not be accessed.

If the Consumer does not reconnect within an acceptable amount of time, the Payment Handler's system may perform local failure resolution in order to close the transaction and to retain resources for other transactions ("Change Process State"). If the Consumer reconnect afterwards, an IOTP Payment Response or IOTP Error Block could be generated.

IOTP Wallet Initialization

At startup or on explicit user request the IOTP Application Core should check its IOTP Payment Bridges' internal status by searching for pending payment transactions.

1. The IOTP Application Core interrogates the registered IOTP Payment

  Bridges about pending payment transactions.  The IOTP Application
  Core may store indicators for pending transactions and use them
  for driving any subsequent inquiry ("Inquire Pending Payment").

2. If one or more IOTP Payment Bridges report the presence of pending

  transactions, the IOTP Application Core may try to suspend
  ("Change Process State") or resume (only Consumer: "Resume Payment
  Consumer") the pending transactions (on user request).

The IOTP Payment Bridge may deny the processing of any new payment transactions until the pending transactions have been processed. Such denials are signaled by the error code "Business Error".

Payment Software Management

The IOTP Application Core provides only a simple and generic interface for the registration of new payment methods / instruments ("Manage Payment Software"). It receives the initial user request and defers the actual registration to the corresponding IOTP Payment Bridge.

The IOTP Application Core may also activate the Existing Payment Software for further payment instrument and wallet administration.

Mutuality

The Payment API is formalized using the eXtensible Markup Language (XML). It defines wrapper elements for both the input parameters and the API function's response. In particular, the response wrapper provides common locations for Error Codes and Error Descriptions.

It is anticipated that this description reflects the logical structure of the API parameter and might be used to derive implementation language specific API definitions.

XML definition:

<!ELEMENT IotpPaymentApiRequest (

 FindAcceptedPaymentBrand |
 FindAcceptedPaymentProtocol |
 GetPaymentInitializationData |
 FindPaymentInstrument |
 CheckPaymentPossiblity |
 StartPaymentConsumer |
 StartPaymentPaymentHandler |
 ResumePaymentConsumer |
 ResumePaymentPaymentHandler |
 ContinueProcess |
 InquireProcessState |
 ChangeProcessState |
 InquireAuthChallenge |
 Authenticate |
 CheckAuthResponse |
 CheckPaymentReceipt |
 ExpandPaymentReceipt |
 RemovePaymentLog |
 PaymentInstrumentInquiry |
 InquirePendingPayment |
 ManagePaymentSoftware |
 StartPaymentInquiry |
 InquirePaymentStatus |
 CallBack )>

<!ATTLIST IotpPaymentApi

 xml:lang          NMTOKEN   #IMPLIED
 ContentSoftwareID CDATA     #IMPLIED
 xmlns             CDATA     #FIXED
                "http://www.iotp.org/2000/08/PaymentAPI" >

<!ELEMENT IotpPaymentApiResponse (ErrorResponse?, (

 FindAcceptedPaymentBrandResponse |
 FindAcceptedPaymentProtocolResponse |
 GetPaymentInitializationDataResponse |
 FindPaymentInstrumentResponse |
 CheckPaymentPossiblityResponse |
 StartPaymentConsumerResponse |
 StartPaymentPaymentHandlerResponse |
 ResumePaymentConsumerResponse |
 ResumePaymentPaymentHandlerResponse |
 ContinueProcessResponse |
 InquireProcessStateResponse |
 ChangeProcessStateResponse |
 InquireAuthChallengeResponse |
 AuthenticateResponse |
 CheckAuthResponseResponse |
 CheckPaymentReceiptResponse |
 ExpandPaymentReceiptResponse |
 RemovePaymentLogResponse |
 PaymentInstrumentInquiryResponse |
 InquirePendingPaymentResponse |
 ManagePaymentSoftwareResponse |
 StartPaymentInquiryResponse |
 InquirePaymentStatusResponse |
 CallBackResponse )?)>

<!ATTLIST IotpPaymentApiResponse

 xml:lang          NMTOKEN #IMPLIED
 ContentSoftwareID CDATA   #IMPLIED
 xmlns             CDATA   #FIXED
            "http://www.iotp.org/2000/08/PaymentAPI" >

<!ELEMENT ErrorResponse (ErrorLocation+,PaySchemePackagedContent*) > <!ATTLIST ErrorResponse

 xml:lang      NMTOKEN   #IMPLIED
 ErrorCode     NMTOKEN   #REQUIRED
 ErrorDesc     CDATA     #REQUIRED
 Severity(Warning |
   TransientError |
          HardError)     #REQUIRED
 MinRetrySecs  CDATA     #IMPLIED
 SwVendorErrorRef CDATA  #IMPLIED >

Most of the attribute items are intended for immediate insertion in the IOTP Error Block. The attribute values of the Error Location elements attribute have to enriched and transformed into Error Location Elements of the Error Component (cf. IOTP Specification).

Attributes (cf. IOTP Specification):

xml:lang Defines the language used by attributes or

                  child elements within this component, unless
                  overridden by an xml:lang attribute on a child
                  element.

ContentSoftwareId Contains information which identifies the

                  software that generated the content of the
                  element.  Its purpose is to help resolve
                  interoperability problems that might occur as
                  a result of incompatibilities between messages
                  produced by different software.  It is a single
                  text string in the language defined by
                  "xml:lang".  It must contain, as a minimum
                  problems that might occur as a result of
                  o  the name of the software manufacturer,
                  o  the name of the software,
                  o  the version of the software, and
                  o  the build of the software.

ErrorCode Contains an error code which indicates the

                  nature of the error in the message in error.
                  Valid values for the Error Code are given in
                  the following section.  This mnemonic enables
                  the automatic failure resolution of the IOTP
                  Application Core which analyzes the error code
                  value in order to determine the continuation
                  alternatives.

ErrorDesc Contains a description of the error in the

                  language defined by xml:lang.  The content of
                  this attribute is defined by the
                  vendor/developer of the software that
                  generated the Error Response Element.
                  It is intended for user display and provides
                  detailed explanations about the failure and
                  its (out-of-band) resolution alternatives.

Severity Indicates the severity of the error. Valid

                  values are:
                  o  Warning.  This indicates that although there
                     is a message in error the IOTP Transaction
                     can still continue.
                  o  TransientError.  This indicates that the
                     error in the message in error may be
                     recovered if the message in error that is
                     referred to by the "Names" attribute is
                     resent.
                  o  HardError.  This indicates that there is an
                     unrecoverable error in the message in error
                     and the IOTP Transaction must stop.

MinRetrySecs This attribute should be present if "Severity"

                  is set to "TransientError".  It is the minimum
                  number of whole seconds which the IOTP aware
                  application which received the message
                  reporting the error should wait before
                  resending the message in error identified by
                  the "ErrorLocation" attribute.
                  If Severity is not set to
                  "TransientError" then the value of this
                  attribute is ignored.

SwVendorErrorRef This attribute is a reference whose value is

                  set by the vendor/developer of the software
                  that generated the Error Element.  It should
                  contain data that enables the vendor to
                  identify the precise location in their
                  software and the set of circumstances that
                  caused the software to generate a message
                  reporting the error.

Content:

ErrorLocation This identifies, where possible, the

                  element and attribute in the message
                  in error that caused the Error
                  Element to be generated.  If the
                  "Severity" of the error is not
                  "TransientError", more that one
                  "ErrorLocation" may be specified as
                  appropriate depending on the nature
                  of the error and at the discretion of
                  the vendor/developer of the IOTP
                  Payment Bridge.
                  Its definition coincides with the
                  IOTP specification whereby the
                  attributes "IotpMsgRef", "BlkRef" and
                  "CompRef" are left blank,
                  intentionally.

PaySchemePackagedContent cf. Table 5

Error Codes

The following table lists the valid values for the ErrorCode attribute of the Error Response Element. The first sentence of the error description contains the default text that can be used to describe the error when displayed or otherwise reported. Individual implementations may translate this into alternative languages at their discretion. However, not every error code may apply to every API call. An Error Code must not be more than 14 characters long. The Error Codes have been taken from the IOTP Specification and extended by some additional codes which are highlighted by a preceding asterisk.

Generally, if the corrupt values have been user supplied, the IOTP Application Core might prompt for their correction. If the renewal fails or if the IOTP Application Core skips any renewals and some notification has to be send to the counter-party, the error code is encapsulated within an IOTP Error Block.

However, the IOTP server application reports business errors - visible at the IOTP layer - in the Status Component of the respective Response Block.

The IOTP Application Core may add the attributes (and values) within the ErrorLocation elements that are omitted by the IOTP Payment Bridge.

The following table mentions any modification from this general processing for particular error values. Furthermore, it contains hints for developers of IOTP Application Core software components about the processing of error codes. Conversely, developers of IOTP Payment Bridges get impressions about the expected behavior of the IOTP Application Core.

The IOTP Payment API assumes that the IOTP Application Core implements the dialog boxes needed for error resolution. But it does not assume, that the IOTP Payment Bridge actually relies on them. Instead, the IOTP Payment Bridge may try resolution on its own, may implement specific dialog boxes, and may signal only final failures.

Note: This abstract document assumes that the API parameters are exchanged XML encoded. Therefore, several error values might disappear in lower level language specific derivations.

Error Value Error Description


-----------------

Reserved Reserved. This error is reserved by the

                  vendor/developer of the software.  Contact
                  the vendor/developer of the software for
                  more information (see the SoftwareId
                  attribute of the Message Id element in the
                  Transaction Reference Block [IOTP]).

XmlNotWellFrmd XML not well formed. The XML document is not

                  well formed.  See [XML] for the meaning of
                  "well formed".

XmlNotValid XML not valid. The XML document is well

                  formed but the document is not valid.  See
                  [XML] for the meaning of "valid".
                  Specifically:
                  o  the XML document does not comply with the
                     constraints defined in the IOTP document
                     type declaration, and
                  o  the XML document does not comply with the
                     constraints defined in the document type
                     declaration of any additional [XML-NS]
                     that are declared.
                  The Names attribute might refer some
                  attributes and elements of the input
                  parameter list.

(*)ElNotValid Element not valid. Invalid element in terms

                  of prescribed syntactical characteristics.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  elements (if they have ID attributes).
                  The IOTP Application Core has to replace the
                  error code with "XmlNotValid" before
                  transmission to the counterparty.

ElUnexpected Unexpected element. Although the XML

                  document is well formed and valid, an
                  element is present that is not expected in
                  the particular context according to the
                  rules and constraints contained in this
                  specification.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  elements (if they have ID attributes).

ElNotSupp Element not supported. Although the document

                  is well formed and valid, an element is
                  present that
                  o  is consistent with the rules and
                     constraints contained in this
                     specification, but
                  o  is not supported by the IOTP Aware
                     Application which is processing the IOTP
                     Message.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  elements (if they have ID attributes).

ElMissing Element missing. Although the document is

                  well formed and valid, an element is missing
                  that should have been present if the rules
                  and constraints contained in this
                  specification are followed.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  elements (if they have ID attributes).

ElContIllegal Element content illegal. Although the

                  document is well formed and valid, the
                  element contains values which do not conform
                  the rules and constraints contained in this
                  specification.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  element (if they have ID attributes).
                  The IOTP Application Core has to replace the
                  Error Code with "ElNotSupp" before
                  transmission to the counter party, if the
                  ErrorLocation elements refer to
                  non-PackagedContent element.

EncapProtErr Encapsulated protocol error. Although the

                  document is well formed and valid, the
                  Packaged Content of an element contains data
                  from an encapsulated protocol which contains
                  errors.
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  element (if they have ID attributes).

AttUnexpected Unexpected attribute. Although the XML

                  document is well formed and valid, the
                  presence of the attribute is not expected in
                  the particular context according to the
                  rules and constraints contained in this
                  specification.
                  The AttName attributes of ErrorLocation
                  elements might refer to the corresponding
                  attribute tags.

(*)AttNotValid Attribute not valid. Invalid attribute value

                  in terms of prescribed syntactical
                  characteristics.
                  The AttName attributes of ErrorLocation
                  elements might refer to the corresponding
                  attribute tags.
                  The IOTP Application Core has to replace the
                  error code with "XmlNotValid" before
                  transmission to the counter party.

AttNotSupp Attribute not supported. Although the XML

                  document is well formed and valid, and the
                  presence of the attribute in an element is
                  consistent with the rules and constraints
                  contained in this specification, it is not
                  supported by the IOTP Aware Application
                  which is processing the IOTP Message.

AttMissing Attribute missing. Although the document is

                  well formed and valid, an attribute is
                  missing that should have been present if the
                  rules and constraints contained in this
                  specification are followed.
                  The AttName attributes of ErrorLocation
                  elements might refer to the corresponding
                  attribute tags.
                  If the attribute is required by the IOTP
                  Document Type Declaration (#REQUIRED) the
                  hints for non-valid attributes should be
                  adopted, otherwise these for illegal
                  attribute values.

AttValIllegal Attribute value illegal. The attribute

                  contains a value which does not conform to
                  the rules and constraints contained in this
                  specification.
                  The AttName attributes of ErrorLocation
                  elements might refer to the corresponding
                  attribute tags - valid values are:
                  BrandId: illegal/unknown Brand Identifier -
                  If the brand is not recognized/known by any
                  IOTP Payment Bridge, the IOTP Application
                  Core may offer the registration of a new
                  Payment Instrument.
                  PaymentInstrumentId: illegal/unknown
                  Payment Instrument Identifier - This
                  indicates a serious communication problem if
                  the attribute value has been reported by the
                  same "wallet" on a previous inquiry
                  requests.  The IOTP Application Core has to
                  replace the error code with
                  "UnknownError" before transmission to the
                  counter party.
                  WalletId: illegal/unknown Wallet Identifier
                  - It is assumed that the wallet identifier
                  is checked before the pass phrase.  On
                  invalid wallet identifiers, the IOTP
                  Application Core may open the dialog in
                  order to request the correct wallet
                  identifier.  In addition, any pass phrase may
                  be supplied by the user.  The dialog should
                  indicate the respective payment brand(s).
                  The IOTP Application Core has to replace the
                  error code with "UnknownError" before
                  transmission to the counter party.
                  Passphrase:   illegal/unknown Pass Phrase -
                  The IOTP Application Core may open the
                  dialog in order to request the correct pass
                  phrase.  If the pass phrase is wallet
                  identifier specific the dialog should
                  display the wallet identifier.  The IOTP
                  Application Core has to replace the error
                  code with "TransportError" before
                  transmission to the counter party.
                  Action:  illegal / unknown / unsupported
                  Action
                  PropertyTypeList:  lists contains illegal /
                  unknown / unsupported Property Types - The
                  IOTP Application Core tries only the local
                  resolution but does never transmit any IOTP
                  Error Block to the counter party.
                  CurrCode: illegal/unknown/unsupported
                  Currency Code
                  CurrCodeType: illegal/unknown/unsupported
                  Currency Code Type
                  Amount: illegal/unknown/unsupported Payment
                  Amount
                  PayDirection: illegal/unknown/unsupported
                  Payment Direction
                  ProtocolId:   illegal/unknown/unsupported
                  Protocol Identifier
                  OkFrom: illegal/unknown/unsupported OkFrom
                  Timestamp
                  OkTo:   illegal/unknown/unsupported OkTo
                  Timestamp
                  ConsumerPayId: illegal/unknown Consumer
                  Payment Identifier
                  PaymentHandlerPayId: illegal/unknown Payment
                  Handler Payment Identifier
                  PayId: illegal/unknown Payment Identifier

AttValNotRecog Attribute Value Not Recognized. The

                  attribute contains a value which the IOTP
                  Aware Application generating the message
                  reporting the error could not recognize.
                  The AttName attributes of ErrorLocation
                  elements might refer to the corresponding
                  attribute tags.

MsgTooLarge Message too large. The message is too large

                  to be processed by the IOTP Payment Bridge
                  (or IOTP Application Core).

ElTooLarge Element too large. The element is too large

                  to be processed by the IOTP Payment Bridge
                  (or IOTP Application Core).
                  The ElementRef attributes of ErrorLocation
                  elements might refer to the corresponding
                  elements.

ValueTooSmall Value too small or early. The value of all

                  or part of an element content or an
                  attribute, although valid, is too small.
                  The ErrorLocation elements might refer to
                  the corresponding attribute tags or
                  elements.

ValueTooLarge Value too large or in the future. The value

                  of all or part of an element content or an
                  attribute, although valid, is too large.
                  The ErrorLocation elements might refer to
                  the corresponding attribute tags or
                  elements.

ElInconsistent Element Inconsistent. Although the document

                  is well formed and valid, according to the
                  rules and constraints contained in this
                  specification:
                  o  the content of an element is inconsistent
                     with the content of other elements or
                     their attributes, or
                  o  the value of an attribute is inconsistent
                     with the value of one or more other
                     attributes.
                  The Error Description may contain further
                  explanations.
                  The ErrorLocation elements might refer to
                  the corresponding attribute tags or elements
                  that are inconsistent.

TransportError Transport Error. This error code is used to

                  indicate that there is a problem with the
                  transport mechanism that is preventing the
                  message from being received.  It is typically
                  associated with a "Transient Error".
                  The connection to some periphery or the
                  counter party could not be established,
                  is erroneous, or has been lost.
                  The Error Description may contain further
                  narrative explanations, e.g., "chip card
                  does not respond", "remote account manager
                  unreachable", "Internet connection to xyz
                  lost", "no Internet connection available",
                  "no modem connected", or "serial port to
                  modem used by another application".  This
                  text should be shown to the end user.  If
                  timeout has occurred at the Consumer this
                  text should be shown and the Consumer may
                  decide how to proceed - alternatives are
                  retry, payment transaction suspension, and
                  cancellation.

MsgBeingProc Message Being Processed. This error code is

                  only used with a Severity of Transient
                  Error.  It indicates that the previous
                  message, which may be an exchange message or
                  a request message, is being processed and,
                  if no response is received by the time
                  indicated by the "MinRetrySecs" attribute,
                  then the original message should be resent.

SystemBusy System Busy. This error code is only used

                  with a Severity of Transient Error.  It
                  indicates that the IOTP Payment Bridge or
                  Existing Payment Software that received the
                  API request is currently too busy to handle
                  it.  If no response is received by the time
                  indicated by the "MinRetrySecs" attribute,
                  then the original message should be resent.
                  The Error Description may provide further
                  explanations, e.g., "wallet / chip card
                  reader is unavailable or locked by another
                  payment transaction", "payment gateway is
                  overloaded", "unknown chip card reader", or
                  "unrecognized chip card inserted, change
                  chip card".
                  The Consumer's IOTP Application Core may
                  display the error description and ask the
                  Consumer about the continuation -
                  alternatives are retry, payment transaction
                  suspension, and cancellation.

UnknownError Unknown Error. Indicates that the

                  transaction cannot complete for some reason
                  that is not covered explicitly by any of the
                  other errors.  The Error description
                  attribute should be used to indicate the
                  nature of the problem.
                  The ErrorLocation elements might refer to
                  the corresponding attribute tags or elements
                  that are inconsistent.

(*)SyntaxError Syntax Error. An (unknown) syntax error has

                  occurred.
                  The ErrorLocation elements might refer to
                  the corresponding attribute tags or elements
                  that are inconsistent.
                  The IOTP Application Core has to replace the
                  error code with "XmlNotValid" or
                  "UnknownError" before transmission to the
                  counter party.

(*)ReqRefused Request refused. The API request is

                  (currently) refused by the IOTP Payment
                  Bridge.  The error description may provide
                  further explanations, e.g., "wallet / chip
                  card reader is unavailable or locked by
                  another payment transaction", "payment
                  gateway is overloaded", "unknown chip card
                  reader", or "unrecognized chip card
                  inserted, change chip card".
                  The Consumer's IOTP Application Core may
                  display the error description and ask the
                  Consumer about the continuation -
                  alternatives are retry, payment transaction
                  suspension, and cancellation.  Denials due to
                  invalid Process States should be signaled by
                  "BusinessError".  Typically, this kind of
                  error is not passed to the counter party's
                  IOTP Application Core.  Otherwise, it maps to
                  "TransportError" or "UnknownError".

(*)ReqNotSupp Request not supported. The API

                  function(ality) has not been implemented in
                  the IOTP Payment Bridge.  Typically, this
                  kind of error is not passed to the
                  counter party's IOTP Application Core.
                  Otherwise, it maps to "TransportError" or
                  "UnknownError".

(*)BusError Business Error. The API request has been

                  rejected because some payment transaction
                  has an illegal payment status.
                  Particularly, this error code is used to
                  signal any raise of payment business layered
                  failures.
                  The ErrorLocation elements may refer to
                  payment transactions using the party's
                  Payment Identifier - it defaults to the
                  current transaction or might contain the
                  current payment transaction party's Payment
                  Identifier - identified by the ElementRef
                  attribute while the AttName attribute is
                  fixed with "PayId".
                  The IOTP Application Core must inquire the
                  IOTP Payment Bridge about the actual Process
                  State which actually encodes the business
                  error ("Inquire Process State").
                  This error code must not be
                  passed to the counter party's IOTP
                  Application Core.
                    Table 2: Common Error Codes

The IOTP Payment Bridge may also use the error description in order to notify the Consumer about further necessary steps for failure resolution, e.g., "Sorry, your payment transaction failed. Unfortunately, you have been charged, please contact your issuer."

Attributes and Elements

The following table explains the XML attributes in alphabetical order - any parenthesized number after the attribute tag is a recommended maximal length of the attribute value in characters:

Attribute Description


-----------

Amount (11) Indicates the payment amount to be paid in AmountFrom(11) whole and fractional units of the currency. AmountTo (11) For example $245.35 would be expressed

                   "245.35".  Note that values smaller than the
                   smallest denomination are allowed.  For
                   example one tenth of a cent would be
                   "0.001".

AuthenticationId An identifier specified by the

                   authenticator which, if returned by the
                   organization that receives the
                   authentication request, will enable the
                   authenticator to identify which
                   authentication is being referred to.

BrandId (128) This contains a unique identifier for the

                   brand (or promotional brand).  It is used to
                   match against a list of Payment Instruments
                   which the Consumer holds to determine
                   whether or not the Consumer can pay with the
                   Brand.
                   Values of BrandId are managed under
                   procedure being described in the IOTP
                   protocol specification.

BrandLogoNetLocn The net location which can be used to

                   download the logo for the organization (cf.
                   IOTP Specification).
                   The content of this attribute must conform
                   to [URL].

BrandName This contains the name of the brand, for

                   example "MasterCard Credit".  This is the
                   description of the Brand which is displayed
                   to the consumer in the Consumer's language
                   defined by "xml:lang".  For example it might
                   be "American Airlines Advantage Visa".  Note
                   that this attribute is not used for matching
                   against the payment instruments held by the
                   Consumer.

BrandNarrative This optional attribute is

                   used by the Merchant to indicate some
                   special conditions or benefit which would
                   apply if the Consumer selected that brand.
                   For example "5% discount", "free shipping
                   and handling", "free breakage insurance for
                   1 year", "double air miles apply", etc.

CallBackFunction A function which is called whenever there is

                   a change of Process State or payment
                   progress, e.g., for display updates.  However,
                   the IOTP Payment Bridge may use its own
                   mechanisms and dialog boxes.

CallBackLanguageList

                   A list of language codes which contain, in
                   order of preference, the languages in which
                   the text passed to the Call Back function
                   will be encoded.

CompletionCode (14) Indicates how the process completed.

                   It is required if ProcessState is set to
                   "Failed" otherwise it is ignored.  Valid
                   values as well as recovery options are given
                   in the IOTP specification.
                   The IOTP Payment Bridge may also use the
                   Status Description to notify the Consumer
                   about further necessary steps in order to
                   resolve some kind of business failures,
                   e.g.,
                   o  "sorry, your payment transaction failed.
                      Unfortunately, you have been charged,
                      please contact your issuer."
                   o  "insufficient capacity left (on your
                      stored value card) for refund",
                   o  "payment failed/chip card error/internal
                      error, please contact your payment
                      instrument's issuer"

ConsumerDesc A narrative description of the Consumer.

ConsumerPayId (14) An unique identifier specified by the

                   Consumer that, if returned by the Payment
                   Handler in another Payment Scheme Component
                   or by other means, enables the Consumer to
                   identify which payment is being referred to.
                   This unique identifier is generated by the
                   IOTP Application Core and submitted to the
                   IOTP Payment Bridge on every API call.  It
                   may equal the Payment Handler Payment
                   Identifiers but need not necessarily be so.
                   The uniqueness extends to multiple payment
                   instruments, payment brands, payment
                   protocols, wallet identifiers, and even
                   multiple IOTP Payment Bridges.

ContStatus During payment progress, this status value

                   indicates whether the payment needs to be
                   continued with further IOTP Payment Scheme
                   Component exchanges with the remote party.
                   "End" indicates that the reported payment
                   scheme data is the last data to be exchanged
                   with the counter party.

ContentSoftwareId This contains information that identifies

                   the software that generated the content of
                   the element.  Its purpose is to help resolve
                   interoperability problems that might occur
                   as a result of incompatibilities between
                   messages produced by different software.  It
                   is a single text string in the language
                   defined by xml:lang.  It must contain, as a
                   minimum:
                   o  the name of the software manufacturer,
                   o  the name of the software,
                   o  the version of the software, and
                   o  the build of the software.

CurrCodeType (14) Indicates the domain of the CurrCode. This

                   attribute is included so that the currency
                   code may support nonstandard currencies
                   such as frequent flyer point, trading
                   stamps, etc.  Its values may be
                   o  ISO-4217-A, the default, indicates the
                      currency code is the three-letter
                      alphabetic code that conform to ISO-4217
                      [ISO4217].
                   o  IOTP indicates that the values of
                      CurrCode are managed under the procedure
                      described in [IOTP].

CurrCode (14) A code which identifies the currency to be

                   used in the payment.  The domain of valid
                   currency codes is defined by "CurrCodeType"

MerchantPayId (14) An private identifier specified by the

                   Merchant which will enable the Merchant to
                   identify which payment is being referred to.
                   It is a pure private item and is never sent
                   to any other party.  It is provided by the
                   IOTP Payment Bridge on payment preparation
                   during brand compilation.
                   Cf. To "ConsumerPayId" for note about
                   uniqueness.

MerchantOrgId (64) A local item that might refer to some

                   specific shop in a multi shop environment.
                   This item is optional and might enrich the
                   Wallet Identifier which itself can be used
                   for the same purpose.

Name Distinguishes between multiple occurrences

                   of Packaged Content Elements at the same
                   point in IOTP.  For example:
                   <ABCD>
                     <PackagedContent Name='FirstPiece'>
                       snroasdfnas934k
                     </PackagedContent>
                     <PackagedContent Name='SecondPiece'>
                       dvdsjnl5poidsdsflkjnw45
                     </PackagedContent>
                   </ABCD>
                   The "Name" attribute may be omitted, for
                   example if there is only one Packaged
                   Content element.

OkFrom (30) The date and time in UTC Format range OkTo (30) indicated by the merchant in which the

                   Payment Handler may accept the payment.
                   For more information, see [UTC].

Passphrase (32) Payment wallets may use pass phrase

                   protection for transaction data and payment
                   instruments' data.  However, it is assumed
                   that there exists a public and customizable
                   payment instrument identifier such that
                   these identifiers together with their
                   relationship to payment brands, payment
                   protocols, payment directions, and currency
                   amounts can be queried by the IOTP
                   application without any pass phrase
                   knowledge.

PayDirection Indicates the direction in which the

                   payment for which a Brand is being selected
                   is to be made.  Its values may be:
                   o  Debit: The sender of the Payment Request
                      Block (e.g., the Consumer) to which this
                      Brand List relates will make the payment
                      to the Payment Handler, or
                   o  Credit: The sender of the Payment Request
                      Block to which this Brand List relates
                      will receive a payment from the Payment
                      Handler.

PayId (14) This attribute is introduced for API

                   simplification:
                   o  The Consumer has to identify PayId and
                      ConsumerPayId.
                   o  The Merchant has to identify PayId and
                      MerchantPayId.
                   o  The Payment Handler has to identify PayId
                      and Payment Handler Pay Id.

PayInstId This contains the unique identifier used

                   internally by the IOTP Payment
                   Bridge/Existing Payment Software.

PayInstName This contains the user-defined name of the

                   payment instrument.  There exist no
                   (technical) constraints like uniqueness.  The
                   "xml:lang" attribute denotes the language
                   encoding of its value.

PaymentHandlerDesc A narrative description of the Payment

                   Handler.

PaymentHandlerPayId An unique identifier specified by the

 (14)              Payment Handler that, if returned by the
                   Consumer in another Payment Scheme Component
                   or by other means, enables the Payment
                   Handler to identify which payment is being
                   referred to.  It is required whenever it is
                   known.
                   Cf. To "ConsumerPayId" for note about
                   uniqueness.

PaymentInstrumentId An identifier for a specific payment

 (32)              instrument, e.g., "credit card", "Mondex card
                   for English Pounds".  This identifier is
                   fully customizable.  It is assumed, that it
                   does not contain confidential information or
                   even an indication of it.  The payment
                   instrument identifier is unique within each
                   payment brand.  It is displayed to the
                   Consumer during brand selection.

PayReceiptNameRefs Optionally contains element references to

 (32)              other elements (containing payment scheme
                   specific data) that together make up the
                   receipt.  Note that each payment scheme
                   defines in its supplement the elements that
                   must be referenced
                   The IOTP Application Core should save all
                   the components referenced so that the
                   payment receipt can be reconstructed when
                   required.

PayReqNetLocn The Net Location indicating where an

                   unsecured Payment Request message should be
                   sent if this protocol choice is used.
                   The content of this attribute must conform
                   to [URL] and depends on the Transport
                   Mechanism.

PercentComplete (3) A number between 0 and 100 which indicates

                   the progress of the payment transaction.  The
                   values range between 0 and 99 for pending
                   and suspended transactions.

ProcessState Contains a Process State Code that

                   indicates the current state of the process
                   being carried out.  Valid values are:
                   o  NotYetStarted.  The Payment Request Block
                      has been received but processing of the
                      Payment Request has not yet started
                   o  InProgress.  The payment transaction is
                      pending.  The processing of the (Payment)
                      Request Block has started but it is not
                      yet complete.
                   o  (*)Suspended: The payment transaction has
                      been suspended and can be resumed.
                   This process state is mapped to
                   "InProgress", if it is passed to the
                   counter party's IOTP Application Core.
                   o  CompletedOk.  The processing of the (Payment)
                      Request Block and any following Payment
                      Exchange Blocks has completed successfully.
                   o  Failed.  The payment processing has finally
                      failed for a Business Error.
                   o  ProcessError.  This value is only used
                      when the Status Component is being used in
                      connection with an Inquiry Request Trading
                      Block.  It indicates there was a Technical
                      Error in the Request Block which is being
                      processed or some internal processing
                      error.  Each party's IOTP Payment Bridge
                      uses this value in order to notify the
                      IOTP Application Core about the presence
                      of technical errors.

PropertyType (14) The property type defines codes used for

                   interrogation of specific properties about a
                   payment instrument.  They are unique for each
                   payment brand.  The predefined property "all"
                   is used on general inquiries.  However, these
                   property types are not used during normal
                   payment processing.  E.g., they may apply to
                   payment brand specific transactions or
                   out-of-band failure resolution.

PropertyDesc The property description carries the

                   respective human readable property (value)'s
                   description.

PropertyValue The actual property value intends automatic

                   post processing.

ProtocolBrandId (64)This is an identifier to be used with a

                   particular payment protocol.  For example,
                   SET and EMV have their own well defined, yet
                   different, values for the Brand identifier
                   to be used with each protocol.  The valid values
                   of this attribute are defined in the
                   supplement for the payment protocol
                   identified by "ProtocolId" that describes
                   how the payment protocol works with IOTP.
                   Identifier maps to at most one Protocol
                   Brand Identifier.

ProtocolId (64) An identifier for a specific payment

                   protocol and version, e.g., "SETv1.0",
                   "ecash".  Valid values are defined by
                   supplements to the IOTP specification and
                   they are unique within each payment brand.

ProtocolIds A sequence of Protocol Identifiers

ProtocolName A narrative description of the payment

                   protocol and its version in the language
                   identified by "xml:lang".  For example
                   "Secure Electronic Transaction Version 1.0".
                   Its purpose is to help provide information
                   on the payment protocol being used if
                   problems arise.

SecPayReqNetLocn The Net Location indicating where a secured

                   Payment Request message should be sent if
                   this protocol choice is used.
                   A secured payment involves the use of a
                   secure channel such as [TLS] in order
                   to communicate with the Payment Handler.
                   The content of this attribute must conform
                   to [URL].

ReceiverOrgId The Organization Identification which

                   receives the payment bridge processing
                   Trading Role Data PackagedContent.

StatusDesc (256) An optional textual description of the

                   current process state in the language
                   identified by "xml:lang" that should be
                   displayed to the Consumer.  The usage of this
                   attribute is defined in the payment
                   supplement for the payment method being
                   used.  Particularly, it provides hints for
                   out-of-band failure resolution.  Its length
                   is limited to 256 characters.

StyleSheetNetLocn This contains the net location to a style

                   sheet with visualisation rules for XML
                   encoded data.

TimeStamp (30) The date and time in UTC Format when the

                   payment transaction has been started.
                   For more information on UTC, see [UTC].

WalletId (32) Many existing payment wallet software are

                   multiple wallet capable.  The Wallet
                   Identifier selects the actual wallet.  It is
                   assumed, that the wallet identifier is a
                   public item, that might be stored by the
                   IOTP Application Core.

xml:lang Defines the language used by the Process

                   State Description attribute (cf. IOTP
                   Specification)
                        Table 3: Attributes

The following table explains the XML elements in alphabetical order:

Element Description


-----------

Algorithm This contains information which describes

                   an Algorithm that may be used to generate
                   the Authentication response.
                   The algorithm that may be used is
                   identified by the Name attribute (cf. IOTP
                   Specification).

AuthReqPackagedContent The Authentication Request Packaged

                   Content originates from a Authentication
                   (Data/Response) Component's content
                   whereby the outermost element tags are
                   prefixed with "AuthReq".  Its declaration
                   coincides with the Packaged Content's
                   declaration (cf. IOTP Specification).  It
                   encapsulates the authentication challenge
                   value.  The content of this information is
                   defined in the supplement for a payment
                   protocol.

AuthResPackagedContent The Authentication Response Packaged

                   Content originates from a Authentication
                   Response Component's content whereby the
                   outermost element tags are prefixed with
                   "AuthRes".
                   Its declaration coincides with the
                   Packaged Content's declaration (cf. IOTP
                   Specification).  It encapsulates the
                   authentication response value.  The
                   content of this information is defined in
                   the supplement for a payment protocol.

BrandPackagedContent Container for further payment brand

                   description.  Its content originates from
                   a Brand Element content whose outermost
                   element tags are prefixed with "Brand".
                   Its declaration coincides with the
                   Packaged Content's declaration (cf. IOTP
                   Specification).

BrandSelBrandInfoPackagedContent

                   This contains any additional data that
                   may be required by a particular payment
                   brand.  It forms the content of the Brand
                   Selection Brand Info Element.

BrandSelProtocolAmountInfoPackagedContent

                   This contains any additional data that
                   may be required by a particular payment
                   brand in the format.  It forms the content
                   of the Brand Selection Protocol Amount
                   Info Element.

BrandSelCurrencyAmountInfoPackagedContent

                   This contains any additional data that is
                   payment brand and currency specific in
                   the format.  It forms the content of the
                   Brand Selection Currency Amount Info
                   Element.

MerchantData Any merchant related data that might be

                   used by the IOTP Payment Bridge for
                   different purposes, e.g., it might
                   contain IDs to access some mall data,
                   but not cryptographic keys.  Its Packaged
                   declaration coincides with the Content's
                   declaration (cf. IOTP Specification).

PackagedContent Generic Container for non-IOTP data (cf.

                   IOTP Specification).

PayProtocolPackagedContent

                   The Pay Protocol Packaged Content
                   originates from a Pay Protocol
                   Element's content whereby the outermost
                   element tags are prefixed with
                   "PayProtocol".  It contains information
                   about the protocol which is used by
                   the payment protocol.  The content of
                   this information is defined in the
                   supplement for a payment protocol.  Its
                   declaration coincides with the Packaged
                   Content's declaration (cf. IOTP
                   Specification).

PaySchemePackagedContent

                   The PayScheme Packaged Content originates
                   from a Payment Scheme Component's content
                   whereby the outermost element tags are
                   prefixed with "PayScheme".  Its
                   declaration coincides with the Packaged
                   Content's declaration (cf. IOTP
                   Specification).  It carries the payment
                   specific data.  The content of this
                   information is defined in the supplement
                   for a payment protocol.

ProtocolAmountPackagedContent

                   The Protocol Amount Packaged Content
                   originates from a Protocol Amount
                   Element's content whereby the outermost
                   element tags are prefixed with "Amount".
                   Its declaration coincides with the
                   Packaged Content's declaration (cf. IOTP
                   Specification).  It contains information
                   about the protocol which is used by the
                   payment protocol.  The content of this
                   information is defined in the supplement
                   for a payment protocol.

ProtocolBrandPackagedContent

                   The Protocol Brand Packaged Content
                   originates from a Protocol Brand
                   Element's content whereby the outermost
                   element tags are prefixed with
                   "ProtocolBrand".  Its declaration
                   coincides with the Packaged Content's
                   declaration (cf. IOTP Specification).  It
                   contains information about the brand
                   which might be used by the payment
                   protocol.  The content of this information
                   is defined in the supplement for a
                   payment protocol.

ResponsePackagedContent

                   Container for authentication response
                   data.  Its content originates from a
                   Authentication Response Component's
                   Packaged Content whose outermost element
                   tags are prefixed with "Response".  Its
                   declaration coincides with the Packaged
                   Content's declaration (cf. IOTP
                   Specification).

TradingRoleDataPackagedContent

                   The TradingRoleData Packaged Content
                   originates from a TradingRoleData
                   Component's content whereby the outermost
                   element tags are prefixed with
                   "TradingRoleData".  Its declaration
                   coincides with the Packaged Content's
                   declaration (cf. IOTP Specification).  It
                   contains information from Merchant to
                   Payment Handler via Consumer about the
                   protocol which is used by the payment.
                   The content of this information is
                   defined in the supplement for a payment
                   protocol.  The Name attribute in this
                   packaged contents must include prefix as
                   "Payment:" to indicate that the payment
                   bridge processes this, for example
                   "Payment:SET-OD".  See [SET/IOTP] for
                   more information.
                   The element's declaration coincides with
                   the Packaged Content's declaration (cf.
                   IOTP Specification).
                         Table 4: Elements

XML definition:

<!ENTITY % AuthReqPackagedContent "PackagedContent"> <!ENTITY % AuthResPackagedContent "PackagedContent">

<!ENTITY % BrandPackagedContent "PackagedContent"> <!ENTITY % BrandSelInfoPackagedContent "PackagedContent"> <!ENTITY % BrandSelProtocolAmountPackagedContent

                                       "PackagedContent">

<!ENTITY % BrandSelCurrencyAmountPackagedContent

                                       "PackagedContent">

<!ENTITY % ProtocolAmountPackagedContent

                                       "PackagedContent">

<!ENTITY % PayProtocolPackagedContent "PackagedContent"> <!ENTITY % TradingRoleDataPackagedContent "PackagedContent"> <!ENTITY % MerchantData "PackagedContent"> <!ENTITY % PaySchemePackagedContent "PackagedContent">

Process States

The IOTP Payment API supports six different attribute values that encode the transaction status from the IOTP's point of view, i.e., the appropriate point of view at the interface between the IOTP Application Core and IOTP Payment Bridge. This point of view does not completely mimic the more detailed view on the actual payment by the actual Existing Payment Software or IOTP Payment Bridge.

The following three tables distinguish between the Merchant's, Consumer's, and Payment Handlers' environment. They extend the aforementioned explanations towards the mapping between IOTP process states and the internal payment scheme related states of the Existing Payment Software/IOTP Payment Bridge.

Merchant

The Merchant's point of view of payment is limited to the local payment initiation being interlaced with order processing because IOTP assigns the actual payment processing to the Payment Handler.

ProcessState Description


-----------

NotYetStarted The Payment Transaction exists within the

                   IOTP Application Core, i.e., the
                   Merchant's shop has already signaled to
                   the IOTP Application Core that an IOTP
                   transaction has been initiated by the
                   Consumer.
                   However, neither any API call has been
                   issued to the IOTP Payment Bridge nor has
                   the IOTP Order Request has been created.

InProgress The IOTP Application changes the process

                   state to this value when it issues the
                   first API call to the Payment Bridge
                   during Brand List compilation.
                   This value indicates that the Payment
                   Bridge might have some knowledge about
                   the expected payment or might have
                   performed some preparatory tasks (even
                   with the Payment Handler out-of-band to
                   IOTP).
                   However, this value does not indicate
                   that any IOTP Order Request has been
                   created and transmitted to the Consumer.

Suspended The IOTP transaction has been suspended

                   before the order request block has been
                   transmitted to the Consumer.
                   Implicitly, the payment is also deferred.

CompletedOk The IOTP Order Request has been

                   successfully created and transmitted to
                   the Consumer.  Actually, this process
                   state indicates only that the order
                   processing has been finished.
                   But it contains no indication about the
                   status of the actual payment, which is
                   accepted by the Payment Handler.
                   However, successful order processing
                   signals the IOTP Application Core that a
                   payment with some specific parameters is
                   expected within the near future.  And this
                   signal might be used by the Existing
                   Payment Software for similar purposes.
                   This attribute might be interpreted as
                   successful preparation of the payment
                   system.
                   Particularly, it is expected that the
                   Existing Payment Software maps this IOTP
                   status value to some other internal
                   value, e.g., "NotYetStarted", that is more
                   accurate from its point of view.
                   As IOTP provides no communication channel
                   between the Merchant and Payment Handler,
                   any change of payment process state will
                   be initiated out-of-band to IOTP, e.g., by
                   electronic statements of account or
                   payment scheme specific mechanisms.

Failed The IOTP transaction, i.e., order

                   processing, has failed for some
                   (business) reason and it is known that no
                   payment will occur.
                   This indication might be used to clear
                   all data about this transaction within
                   the Existing Payment Bridge (by
                   "RemovePaymentLog" or
                   "ChangeProcessState") or to reverse any
                   preparation (with the Payment Handler
                   out-of-band to IOTP).
                   However, the ideal point of view of IOTP
                   suspects that the actual payment
                   transaction has been neither started nor
                   initiated.

ProcessError The IOTP transaction, i.e., order

                   processing, has failed for some
                   (technical) reason and it is known that
                   no payment will occur.
                   This indication might be used to clear
                   all data about this transaction within
                   the Existing Payment Bridge (by
                   "RemovePaymentLog" or
                   "ChangeProcessState") or to reverse any
                   preparation (with the Payment Handler
                   out-of-band to IOTP).
                   However, the ideal point of view of IOTP
                   suspects that the actual payment
                   transaction has been neither started nor
                   initiated.
                         Table 5: Merchant

Consumer

The Consumer's IOTP Application Core restricts its point of view to the payment transaction. It is assumed that the IOTP Payment Bridge handles the preceding brand selection process in a stateless manner.

ProcessState Description


-----------

NotYetStarted This encodes the initial process state of

                   any IOTP payment transaction.  This value
                   is set during brand selection but it
                   normally will not change during the whole brand
                   selection process.

InProgress With the issuance of the Start Payment

                   Consumer API call, the IOTP Application
                   Core changes the process state to this
                   value.

Suspended The payment transaction has been

                   suspended.  Suspension may occur anywhere
                   during brand selection (with the
                   Merchant) or payment processing (with the
                   Payment Handler).  On resumption, the IOTP
                   Application Core and the IOTP Payment
                   Bridge have to use other internal data to
                   decide whether brand selection or actual
                   payment processing needs to be continued,
                   i.e., whether the process state needs to
                   be reset to "NotYetStarted" or
                   "InProgress".
                   Note that the Payment API assumes
                   stateless brand selection by the IOTP
                   Payment Bridge.  Typically, any suspension
                   during brand selection requires the
                   repetition of the whole process.  Hereby,
                   the IOTP Application Core might need to
                   consider any already negotiated
                   conditions in a brand depended purchase
                   (brand, protocol).

CompletedOk The successful payment has been

                   acknowledged by the Payment Handler, i.e.,
                   the successful IOTP Payment Response has
                   been received.
                   Implicitly, this implies successful order
                   processing.

Failed The IOTP transaction, i.e., order or

                   payment processing, has failed for some
                   (business) reason.  In either case it is
                   known that the payment will not succeed.

ProcessError The IOTP transaction, i.e., order or

                   payment processing, has failed for some
                   (technical) reason.
                   However, the local process state might be
                   different from that of Payment Handler.
                         Table 6: Consumer

Payment Handler

The Payment Handler is responsible for the actual payment processing. New payment transactions are reported by the Consumer with the transmission of new IOTP Payment Request Blocks. IOTP Payment Exchange Block are send by the Consumer for payment transaction continuation and resumption.

ProcessState Description


-----------

NotYetStarted This encodes the initial process state of

                   any payment transaction.  Typically, this
                   value will last for a short amount of
                   time.

InProgress The IOTP Application Core changes the

                   process state changes to "InProgress"
                   when the Payment Handler starts with the
                   actual processing of the IOTP Payment
                   Request Block.
                   Note that this does not assume that the
                   "StartPaymentPaymentHandler" API function
                   has been called.

Suspended The payment transaction has been

                   suspended.

CompletedOk The payment has been processed,

                   successfully, i.e., the IOTP Payment
                   Response Block was created and
                   transmitted to the Consumer.

Failed The payment transaction, has finally

                   failed for some (business) reason.
                   Note that this value encodes the payment
                   state reported by the IOTP Payment Bridge
                   on "InquireProcessState".  It neither
                   reflects whether the payment receipt has
                   been inquired nor whether the IOTP
                   Payment Response Block has been created
                   and submitted to the Consumer.

ProcessError The payment transaction, has finally

                   failed for some (technical) reason.
                   Note that this value encodes the payment
                   state reported by the IOTP Payment
                   Bridge.  It does not reflect whether some
                   IOTP Error Block has been created and
                   submitted to the Consumer.
                         Table 7: Consumer

Payment API Calls

Brand Compilation Related API Calls

Find Accepted Payment Brand

This API function determines the payment brands being accepted by the Payment Handler on behalf of the Merchant.

Input Parameters

o Payment Direction - provided by the IOTP Application Core o Currency Code and Currency - provided by the IOTP Application

  Core

o Payment Amount - provided by the IOTP Application Core o Merchant Payment Identifier - Merchant's unique private

  reference to the payment transaction

o Merchant Organisation Identifier - used for distinction between

  multiple merchants that share the some IOTP merchant system

o Wallet Identifier - managed by the IOTP Application Core o Merchant Data - specific data used by the IOTP Payment Bridge

  which is managed in the IOTP Application Core.

XML definition:

<!ELEMENT FindAcceptedPaymentBrand (MerchantData*) > <!ATTLIST FindAcceptedPaymentBrand

 PayDirection  (Debit|Credit)  #REQUIRED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 MerchantPayId  CDATA  #REQUIRED
 MerchantOrgId  CDATA  #IMPLIED
 WalletID  CDATA  #IMPLIED >

Output Parameters

o Payment Brand Identifier - for insertion in the Brand List

  Component's Brand Element

o Payment Brand Name and language annotation - for insertion in

  the Brand List Component's Brand Element

o Payment Brand Logo Net Location - for insertion in the Brand

  List Component's Brand Element

o Payment Brand Narrative Description - for insertion in the

  Brand List Component's Brand Element

o (Brand) Packaged Content - further payment brand description

  for insertion in the Brand List Component's Brand Element

The Existing Payment Software returns an empty list of brand items, if it does not support any payment brand/payment protocol combination for the given payment parameters.

XML definition:

<!ELEMENT FindAcceptedPaymentBrandResponse (BrandItem*) > <!ELEMENT BrandItem (BrandPackagedContent*) > <!ATTLIST BrandItem

 BrandId  CDATA  #REQUIRED
 xml:lang  NMTOKEN  #IMPLIED
 BrandName  CDATA  #REQUIRED
 BrandLogoNetLocn  CDATA  #REQUIRED
 BrandNarrative  CDATA  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Find Accepted Payment Protocol

This API function determines the instances of payment protocols (and optionally the payment brands) being accepted by the Payment Handler on behalf of the Merchant. The function might be called in two variants:

o With the Brand Identifier set on the input parameter list: The

  function responds with the payment protocols that fits to the
  submitted brand.

o Without any Brand Identifier - that allows the omission of the

  "Find Accepted Payment Brand" API call (cf. Section 4.1.1): This
  function responds with both the supported brand identifiers and
  the payment protocols being specified by the Brand Elements.

Input Parameters

o Brand Identifier - returned by "Find Accepted Payment Brand" o Payment Direction o Currency Code and Currency o Payment Amount o Merchant Payment Identifier - Merchant's unique private

  reference to the payment transaction

o Merchant Organisation Identifier - used for distinction between

  multiple merchants that share the some IOTP merchant system

o Wallet Identifier - managed by the IOTP Application Core o (Brand) Packaged Content - further payment brand description;

  returned by "Find Accepted Payment Brand"; this elements are
  only provided if the Brand Identifier is set

o Merchant Data - specific data used by the IOTP Payment Bridge

  which is managed in the IOTP Application Core.

XML definition:

<!ELEMENT FindAcceptedPaymentProtocol (BrandPackagedContent*,

 MerchantData?) >

<!ATTLIST FindAcceptedPaymentProtocol

 BrandId  CDATA  #IMPLIED
 PayDirection  (Debit|Credit)  #REQUIRED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 MerchantPayId  CDATA  #REQUIRED
 MerchantOrgId  CDATA  #IMPLIED
 WalletID  CDATA  #IMPLIED >

Output Parameters

o Payment Protocol Identifier - for insertion in the Brand List

  Component's Pay Protocol Element

o Protocol Brand Identifier - for insertion in the Protocol Brand

  Element of the Brand List Component's Brand Element

o Payment Protocol Name and language annotation- for insertion in

  the Brand List Component's Pay Protocol Element

o Payment Request Net Location - for insertion in the Brand List

  Component's Pay Protocol Element

o Secured Payment Request Net Location - for insertion in the

  Brand List Component's Pay Protocol Element

o Brand Item List (cf. Section 4.1.1) - there must be at least

  one element if no brand identifier has been provided on the
  input parameter list.

o (Protocol Amount) Packaged Content - for insertion in the Brand

  List Component's Protocol Amount Element

o (Pay Protocol) Packaged Content - for insertion in the Brand

  List Component's Pay Protocol Element

o Currency Amount element - quite similar to the definition in

  [IOTP], that contain
  - refined Currency Code and Currency - for insertion in the
    Brand List Component's Currency Amount Element
  - refined Payment Amount - for insertion in the Brand List
  Component's Currency Amount Element

o Brand - there must be at least one element in each Protocol

  Item if no brand identifier has been provided on the input
  parameter list.

XML definition:

<!ELEMENT FindAcceptedPaymentProtocolResponse (ProtocolItem+,

 BrandItem*) >

<!ELEMENT ProtocolItem (ProtocolAmountPackagedContent*,

 PayProtocolPackagedContent*
 CurrencyAmount+, Brand*,ProtocolBrand*)>

<!ATTLIST ProtocolItem

 ProtocolId  CDATA  #REQUIRED
 ProtocolBrandId  CDATA  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 ProtocolName  CDATA  #REQUIRED
 PayReqNetLocn  CDATA  #IMPLIED
 SecPayReqNetLocn  CDATA  #IMPLIED >

<!ELEMENT Brand EMPTY > <!ATTLIST Brand

 BrandId  CDATA  #REQUIRED >

<!ELEMENT CurrencyAmount EMPTY > <!ATTLIST CurrencyAmount

 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #IMPLIED
 Amount  CDATA  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Get Payment Initialization Data

This API function provides the remaining initialization data being required by the Consumer's or Payment Handler's Existing Payment Software. This function might be called both for "brand dependent" and "brand independent" transaction types. In either case, this function is called with one particular brand.

Input Parameters

o Brand Identifier - returned by "Find Accepted Payment Brand" o Merchant Payment Identifier - Merchant's unique private

  reference to the payment transaction

o Payment Direction o Currency Code and Currency - from the Brand List Component's

  Currency Amount Element

o Payment Amount - from the Brand List Component's Currency

  Amount Element

o Payment Protocol Identifier - from the Brand List Component's

  Pay Protocol Element

o Protocol Brand Identifier - from the Protocol Brand Element

  which relates to the selected Brand Element, if any

o (TradingRoleData) Receiver Organization Identifier o OkFrom, OkTo - identical to the entries of the Order Component

Merchant Payment Identifier

o Merchant Organisation Identifier - used for distinction between

  multiple merchants that share the some IOTP merchant system

o Wallet Identifier and/or Pass Phrase

Protocol Brand Element

o (Brand) Packaged Content - further payment brand description,

  from the Brand List Component's Brand Element

o (Protocol Amount) Packaged Content - further payment protocol

  description, from the Brand List Component's Protocol Amount
  Element

o (Pay Protocol) Packaged Content - further payment protocol

  description, from the Brand List Component's Pay Protocol
  Element

o (Protocol Brand) Packaged Content - further brand information,

  from the Protocol Brand Element of the Brand List Component
  which relates to the selected Brand Element, if any

o (Order) Packaged Content - further order description, from the

  Order Element

o three Brand Selection Info Packaged Content elements - copied

  from the Brand Selection Component on brand dependent purchases

o Brand - additional data about the payment brand o Protocol Amount - additional data about the payment protocol o Currency Amount - additional payment brand and currency

  specific data

o Merchant Data - specific data used by the IOTP Payment Bridge

  which is managed in the IOTP Application Core.

XML definition:

<!ELEMENT GetPaymentInitializationData (ProtocolBrand?

 BrandPackagedContent*
 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*,
 OrderPackagedContent*,
 BrandSelBrandInfoPackagedContent*,
 BrandSelProtocolAmountInfoPackagedContent*,
 BrandSelCurrencyAmountInfoPackagedContent*,
 MerchantData*) >

<!ATTLIST GetPaymentInitializationData

 BrandId  CDATA  #REQUIRED
 MerchantPayId  CDATA  #REQUIRED
 PayDirection  (Debit|Credit)  #REQUIRED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 ProtocolId  CDATA  #REQUIRED
 OkFrom  CDATA  #REQUIRED
 OkTo  CDATA  #REQUIRED
 ReceiverOrgId  CDATA  #IMPLIED
 MerchantOrgId  CDATA  #IMPLIED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o OkFrom, OkTo - for insertion in the Payment Component o (TradingRoleData) Packaged Content - further payment protocol

  description; the Name Attribute of the packaged Content
  element must include "Payment:" as the prefix,
  for example "Payment:SET-OD".  For more information, see
  [SET/IOTP].

o (Order) Packaged Content - defaults to the supplied order

  packaged content if omitted.

XML definition:

<!ELEMENT GetPaymentInitializationDataResponse (OrderPackagedContent*, TradingRoleDataPackagedContent*) > <!ATTLIST GetPaymentInitializationDataResponse

 OkFrom  CDATA  #IMPLIED
 OkTo  CDATA  #IMPLIED>

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Inquire Authentication Challenge

This API function inquires any payment protocol specific authentication challenge value from the IOTP Payment Bridge. In Baseline IOTP this API function is called by the Merchant (or Financial Institution). The IOTP Application Core may propose a choice of algorithms to the IOTP Payment Bridge. However, the IOTP Payment Bridge may ignore the proposal and select some other algorithm.

The inquiry is assumed to be stateless. E.g., the IOTP Application Core may check the returned algorithm and stop transaction processing without notifying the IOTP Payment Bridge.

The IOTP Application Core may issue several API calls to the IOTP Payment Bridge to build up the IOTP Authentication Request Block. Any subsequently submitted choice of algorithms should be constrained by the accepted algorithms from earlier API responses.

The IOTP Payment Bridge responds with the Business Error Code if it does not provide any (more) authentication algorithms and challenges.

Input Parameters

o Authentication Identifier - the authenticator may provide its

  payment identifier, i.e., Payment Handler or Merchant Payment
  Identifier.

o Wallet Identifier and/or Pass Phrase o set of pre-selected algorithms for authentication

XML definition:

<!ELEMENT InquireAuthChallenge (Algorithm*) > <!ATTLIST InquireAuthChallenge

 AuthenticationId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o list of Authentication Challenge Packaged Contents - for

  insertion into the IOTP Authentication Request Component

o Algorithm Element - for insertion into the IOTP Authentication

  Request Component

XML definition:

<!ELEMENT InquireAuthChallengeResponse (AuthReqPackagedContent*,

 Algorithm) >

Authenticate

The Consumer's IOTP Application Core defers payment protocol specific authentication processing and the current challenge value to the active IOTP Payment Bridge. Alternative authentication algorithms might be tried sequentially or offered to the user for selection.

Note that the IOTP Application Core has to consider both the current context and the algorithm in order to determine the responsible IOTP Payment Bridge.

Failed authentication is reported by the Business Error Code which might trigger the inquiry of the details ("Inquire Process State"). Final failures might be encoded by the process state "Failed".

Input Parameters

o Authentication Identifier o Wallet Identifier and/or Pass Phrase o Authentication Challenge Packaged Content - copied from the

  IOTP Authentication Request Component

o Algorithm Element - copied from the IOTP Authentication Request

  Component

XML definition:

<!ELEMENT Authenticate (Algorithm, AuthReqPackagedContent*) > <!ATTLIST Authenticate

 AuthenticationId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Authentication Response Packaged Content - for insertion into

  the IOTP Authentication Response Component

XML definition:

<!ELEMENT AuthenticateResponse (AuthResPackagedContent*) >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Check Authentication Response

This API function verifies the Consumer's payment protocol specific authentication response. In Baseline IOTP this API function is called by the Merchant (or the Financial Institution). It is called only if the counter party has responded with an IOTP Authentication Response Component within the Authentication Response Block. Of course, the IOTP Application Core traces the need of such an response.

Due to the authentication's statelessness, all parameters (algorithm, challenge and response) are submitted to the IOTP Payment Bridge. Authentication failure is reported by a Process State different from "CompletedOK".

Input Parameters

o Authentication Identifier o Wallet Identifier and/or Pass Phrase o Authentication Challenge Packaged Content - generated by

  previous "Inquire Authentication Challenge" API call

o Algorithm Element o Authentication Response Packaged Content - copied from the

  Authentication Response Component

XML definition:

<!ELEMENT CheckAuthResponse (Algorithm, AuthReqPackagedContent*,

 AuthResPackagedContent*) >

<!ATTLIST CheckAuthResponse

 AuthenticationId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Current Process (Authentication) State o Completion Code o Status Description and its language annotation

XML definition:

<!ELEMENT CheckAuthResponseResponse EMPTY > <!ATTLIST CheckAuthResponseResponse

 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)#REQUIRED
 CompletionCode  NMTOKEN  #IMPLIED
  xml:lang  NMTOKEN  #IMPLIED
  StatusDesc  CDATA  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Brand Selection Related API Calls

Find Payment Instrument

This API function determines which instances of a Payment Brand, e.g., two Mondex cards, are present. The same physical card may even represent multiple payment instruments.

The IOTP Application Core supplies possible payment brand and payment protocol to the IOTP Payment Bridge that has to be considered when the IOTP Payment Bridge searches for appropriate payment instruments. This set represents the (sub)set of payment alternatives being supported by the Merchant. If the IOTP Application Cote has multiple possible payment brand/protocol, it can call this function in turn.

The Existing Payment Software responds with PayInstrument Elements with empty PayInstId attributes if it does not distinguish between different payment instruments for the particular payment alternatives.

Note that the Payment API assumes that the values of the attributes BrandId, ProtocolId, ProtocolBrandId and the currency amount suffice for the determination of the appropriate Packaged Content Element that will be transmitted to the Payment Handler later on.

Input Parameters

o Brand Identifier - copied from the Brand List Component's Brand

  Element

o Payment Protocol Identifier and associated Protocol Brand

  Identifier

o Payment Direction - copied from the Brand List Component o Currency Code and Currency - copied from the Currency Amount

  Element

o Payment Amount - copied from the Currency Amount Element o Consumer Payment Identifier - Consumer's unique reference to

  the current payment transaction

o Wallet Identifier - managed by the IOTP Application Core o (Brand) Packaged Content - further payment brand description;

  copied from the Brand List Component's Brand Element

o (Protocol Brand) Element - further information; copied from the

  Protocol Brand Element of the Brand List Component which
  relates to the Consumer selected Brand Element, if any.

o (Protocol Amount) Packaged Content - further payment protocol

  description, copied from the Brand List Component's Protocol
  Amount Element

o Element (Protocol) Packaged Content - further payment protocol

  description, copied from the Brand List Component's Pay
  Protocol Element

XML definition:

<!ELEMENT FindPaymentInstrument (BrandPackagedContent*,

 ProtocolBrand?,
 PayProtocolPackagedContent*,
 ProtocolAmountPackagedContent*) >

<!ATTLIST FindPaymentInstrument

 BrandId  CDATA  #REQUIRED
 ProtocolId  CDATA  #REQUIRED
 PayDirection  (Debit|Credit)  #REQUIRED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 ConsumerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED >

Output Parameters

o The known Payment Instrument Identifiers, these are internal

  values

o The user-defined names of the payment instrument and their

  language encoding
  The Existing Payment Software responds with an empty list of
  identifiers, either if it does not distinguish between different
  payment instruments or if there are no registered payment
  instruments available despite brand support for at least one
  (unspecified) payment protocol.  In the latter case, the IOTP
  Payment Bridge has to request the registration of a suitable
  payment instrument at a subsequent step of the payment process.

XML definition:

<!ELEMENT FindPaymentInstrumentResponse (PayInstrument*) > <!ELEMENT PayInstrument EMPTY > <!ATTLIST PayInstrument

 Id  CDATA  #REQUIRED
 xml:lang  NMTOKEN  #IMPLIED
 PayInstName  CDATA  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Check Payment Possibility

This API function checks whether a payment (both debit and credit) can go ahead. It can be used, for example, to check

o if there are sufficient funds available in a particular currency

  for an electronic cash payment brand,

o whether there is sufficient value space left on the payment

  instrument for payment refund,

o whether required system resources are available and properly

  configured, e.g., serial ports or baud rate,

o whether environment requirements are fulfilled, e.g., chip card

  reader presence or Internet connection.

If the payment method is based on external components, e.g., magnetic stripe or chip cards, and the check accesses the medium, the existing payment method should not mutually exclusive lock system resources, e.g., serial port or modem, that may also be required by other Existing Payment Software, e.g., multiple payment software components may share the same card reader. If this happens for API internal request processing, the function has to unlock these components prior to return. Otherwise, the payment may not proceed if the Consumer cancels immediately and decides to use another payment instrument. In this event the previous IOTP Payment Bridge is not notified about the change.

This function call happens immediately after the Consumer's payment instrument selection. For example, if the payment instrument is a chip card, that is not inserted in the chip card reader, the Consumer may be prompted for its insertion. However, the Consumer should be able to hit some 'skip' button, if the payment check is part of the actual payment protocol, too. Finally, the IOTP Payment Bridge may provide only a subset of these capabilities or may even directly generate a successful response without any checks.

Input Parameters

o Brand Identifier - user selection o Payment Instrument Identifier - user selection o Currency Code and Currency Code Type - copied from the selected

  Currency Amount Element

o Payment Amount - copied from the selected Currency Amount Element o Payment Direction - copied from the selected Trading Protocol

  Option Block

o Protocol Identifier - copied from the selected Pay Protocol

  Element

o Protocol Brand Identifier - copied from the selected Protocol

  Brand Element of the Brand List Component which relates to the
  selected Brand Element, if any

o Consumer Payment Identifier - Consumer's unique reference to the

  current payment transaction

o Wallet Identifier and/or Pass Phrase o (Brand) Packaged Content - copied from the selected Brand Element o (Protocol Amount) Packaged Content - copied from the selected

  Protocol Amount Element

o (Protocol) Packaged Content - copied from the selected Pay

  Protocol Element

o (Protocol Brand) Packaged Content - copied from the selected

  Protocol Brand Element of the Brand List Component which relates
  to the selected Brand Element, if any

XML definition:

<!ELEMENT CheckPaymentPossibility (BrandPackagedContent*,

 ProtocolBrand?
 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*>

<!ATTLIST CheckPaymentPossibility

 BrandId  CDATA  #REQUIRED
 PaymentInstrumentId  CDATA  #IMPLIED
 PayDirection  (Debit|Credit)  #REQUIRED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 ProtocolId  CDATA  #REQUIRED
 ConsumerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o three Brand Selection Info Packaged Content elements - for

  insertion into the Brand Selection component

o Brand - additional data about the payment brand o Protocol Amount - additional data about the payment protocol o Currency Amount - additional payment brand and currency specific

  data

XML definition:

<!ELEMENT CheckPaymentPossibilityResponse

 (BrandSelBrandInfoPackagedContent*,
 BrandSelProtocolAmountInfoPackagedContent*,
 BrandSelCurrencyAmountInfoPackagedContent*) >

<!ATTLIST CheckPaymentPossibilityResponse >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Payment Transaction Related API calls

These Payment API calls may be made either by the Consumer's or Payment Handler's IOTP Application Core.

Start Payment Consumer

This API function initiates the actual payment transaction at the Consumer side. The IOTP Payment Bridge and the Existing Payment Software perform all necessary initialization and preparation for payment transaction processing. This includes the reservation of external periphery. E.g., 1) the Consumer's chip card reader needs to be protected against access from other software components, 2) the insertion of the chip card may be requested, 3) the Internet connection may be re-established, or 4) the Payment Handler may open a mutual exclusive session to the security hardware.

The IOTP Payment Bridge monitors the payment progress and stores the current payment states such that resumption - even after power failures - remains possible. Note that the IOTP Application Core supplies only a subset of the following input parameter to the associated resumption API function and refers to the payment transaction through the party's payment identifier.

Input Parameters

o Brand Identifier - copied from the selected Brand Element o Payment Instrument Identifier - the user selection o Currency Code and Currency - copied from the selected Currency

  Amount Element

o Payment Amount - copied from the selected Currency Amount

  Element

o Payment Direction - copied from the Brand List Component o Protocol Identifier - copied from the selected Payment Protocol

  Element

o Protocol Brand Element - further information; copied from the

  Protocol Brand Element of the Brand List Component which
  relates to the selected Brand Element, if any

o OkFrom, OkTo - copied from the Payment Component o Consumer Payment Identifier - Consumer's unique reference to

  the current payment transaction

o Wallet Identifier and/or Pass Phrase o Call Back Function - used for end user notification/logging

  purposes

o Call Back Language List. This list is required if the Call Back

  Function is set

o (Brand) Packaged Content - further payment brand description;

  copied from the selected Brand Element's content

o (Protocol Amount) Packaged Content - further payment protocol

  description; copied from the selected Protocol Amount Element's
  content

o (Payment Protocol) Packaged Content - further payment protocol

  description; copied from the selected Pay Protocol Element's
  content

o (Order) Packaged Content - further order description, copied

  from the Order Component

XML definition:

<!ELEMENT StartPaymentConsumer (BrandPackagedContent*,

 ProtocolBrand?
 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*,
 OrderPackagedContent*) >

<!ATTLIST StartPaymentConsumer

 BrandId  CDATA  #REQUIRED
 PaymentInstrumentId  CDATA  #IMPLIED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 PayDirection  (Debit|Credit)  #REQUIRED
 ProtocolId  CDATA  #REQUIRED
 ProtocolBrandId  CDATA  #IMPLIED
 OkFrom  CDATA  #REQUIRED
 OkTo  CDATA  #REQUIRED
 ConsumerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED
 CallBackFunction  CDATA  #IMPLIED
 CallBackLanguageList  NMTOKENS  #IMPLIED >

Output Parameters

o Continuation Status o (Payment Scheme) Packaged Content - for insertion into the

  Payment Scheme Component of the IOTP Payment Request Block

The IOTP Application Core is allowed to reissue this request several times on failed analyses of the response.

XML definition:

<!ELEMENT StartPaymentConsumerResponse

 (PaySchemePackagedContent*) >

<!ATTLIST StartPaymentConsumerResponse

 ContStatus  (End|Continue)  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Start Payment Payment Handler

This API function initializes the Consumer initiated payment transaction at the Payment Handler's side. Similar to the Consumer's system, the IOTP Payment Bridge and the Existing Payment Software perform all necessary initialization and preparation for payment transaction processing.

Input Parameters

o Brand Identifier - copied from the Consumer selected Brand

  Element

o Consumer Payment Identifier - copied from the Payment Scheme

  Component

o Currency Code and Currency - copied from the Consumer selected

  Currency Amount Element

o Payment Amount - copied from the Consumer selected Currency

  Amount Element

o Payment Direction - copied from the Brand List Component o Protocol Identifier - copied from the Consumer selected

  Payment Protocol Element

o Protocol Brand Identifier - copied from the Brand Protocol

  Element of the Brand List Component which relates to the
  Consumer selected Brand Element, if any

o OkFrom, OkTo - copied from the Payment Component o Payment Handler Payment Identifier - Payment Handler's unique

  reference to the current payment transaction

o Merchant Organisation Identifier - copied from the Merchant's

  Organisation Element

o Wallet Identifier - renaming to till identifier neglected -

  and/or Pass Phrase

o Call Back Function - used for end user notification/logging

  purposes

o Call Back Language List. This list is required if the call

  back function is set

o (Brand) Packaged Content - further payment brand description;

  copied from the Consumer selected Brand Element's content

o (Protocol Brand) Packaged Content - further information; copied

  from the Protocol Brand Element of the Brand List Component
  which relates to the Consumer selected Brand Element, if any.

o (Protocol Amount) Packaged Content - further payment protocol

  description; copied from the Consumer selected Protocol Amount
  Element's content

o (Protocol) Packaged Content - further payment protocol

  description; copied from the Consumer selected Pay Protocol
  Element's content

o (TradingRoleData) Packaged Content - further payment protocol

  description; the Name Attribute of the packaged contents must
  include "Payment:" as the prefix, for example "Payment:SET-OD".
  For more information, see [SET/IOTP].

o Three Brand Selection Info Packaged Content Elements - copied

  from the Brand Selection Component

o Brand - additional data about the payment brand o Protocol Amount - additional data about the payment protocol o Currency Amount - additional payment brand and currency

  specific data

o (Payment Scheme) Packaged Content.

XML definition:

<!ELEMENT StartPaymentPaymentHandler (BrandPackagedContent*,

 ProtocolBrand?,
 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*,
 BrandSelBrandInfoPackagedContent*,
 BrandSelProtocolAmountInfoPackagedContent*,
 BrandSelCurrencyAmountInfoPackagedContent*,
 TradingRoleDataPackagedContent*,
 PaySchemePackagedContent*) >

<!ATTLIST StartPaymentPaymentHandler

 BrandId  CDATA  #REQUIRED
 ConsumerPayId  CDATA  #IMPLIED
 CurrCodeType  NMTOKEN  'ISO4217-A'
 CurrCode  CDATA  #REQUIRED
 Amount  CDATA  #REQUIRED
 PayDirection  (Debit|Credit)  #REQUIRED
 ProtocolId  CDATA  #REQUIRED
 OkFrom  CDATA  #REQUIRED
 OkTo  CDATA  #REQUIRED
 PaymentHandlerPayId  CDATA  #REQUIRED
 MerchantOrgId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED
 CallBackFunction  CDATA  #IMPLIED
 CallBackLanguageList  NMTOKENS  #IMPLIED >

Output Parameters

o Continuation Status o (Payment Scheme) Packaged Content - for insertion into the

  Payment Scheme Component of the IOTP Payment Exchange Block

The response message must contain payment schema data if the continuation status signals "Continue". The IOTP Application Core is allowed to reissue this request several times on failed analyses of the response.

XML definition:

<!ELEMENT StartPaymentPaymentHandlerResponse

 (PaySchemePackagedContent*) >

<!ATTLIST StartPaymentPaymentHandlerResponse

 ContStatus  (End|Continue)  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Resume Payment Consumer

This API function resumes a previously suspended payment at the Consumer side. Resumption includes the internal inquiry of the payment transaction data, e.g., payment amount, protocol identifier, and the whole initialization as it has been applied on the "Start Payment Consumer" API request.

It is up to the IOTP Application Core to decide whether an IOTP Payment Request Block or a IOTP Payment Exchange Block needs to be generated. One indicator might be the receipt of a previous IOTP Payment Exchange Block from the Payment Handler, e.g., the knowledge of the Payment Handler Payment Identifier.

Input Parameters

o Consumer Payment Identifier o Wallet Identifier and/or Pass Phrase

o Call Back Function - used for end user notification/logging

  purposes

XML definition:

<!ELEMENT ResumePaymentConsumer EMPTY > <!ATTLIST ResumePaymentConsumer

 ConsumerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED
 CallBackFunction  CDATA  #IMPLIED
 CallBackLanguageList  NMTOKENS  #IMPLIED >

Output Parameters

o Continuation Status o (Payment Scheme) Packaged Content - for insertion in the

  Payment Scheme Component of the next IOTP message (Payment
  Exchange or Request Block).

The IOTP Application Core is allowed to reissue this request several times on failed analyses of the response. However, the IOTP Payment Bridge might reject the resumption request by using the "AttNotSupp" Error Code "naming" the Consumer Payment Identifier attribute. Then the Consumer has to apply normal error processing to the current (sub-)transaction and to issue a new Payment Request Block to the Payment Handler.

XML definition:

<!ELEMENT ResumePaymentConsumerResponse

 (PaySchemePackagedContent*) >

<!ATTLIST ResumePaymentConsumerResponse

 ContStatus  (End|Continue)  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Resume Payment Payment Handler

This API function resumes a payment at the Payment Handler side.

Input Parameters

o Payment Handler Payment Identifier o Wallet Identifier - renaming to till identifier neglected - and

  Pass Phrase

o Call Back Function - used for end user notification/logging

  purposes

o Call Back Language List. This list is required if the Call Back

  Function is set

o (Payment Scheme) Packaged Content - copied from the Payment

  Scheme Component of the received IOTP message (Payment Exchange
  or Request Block).

XML definition:

<!ELEMENT ResumePaymentPaymentHandler

 (PaySchemePackagedContent*) >

<!ATTLIST ResumePaymentPaymentHandler

 PaymentHandlerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED
 CallBackFunction  CDATA  #IMPLIED
 CallBackLanguageList  NMTOKENS  #IMPLIED >

Output Parameters

o Continuation Status o (Payment Scheme) Packaged Content - for insertion in the

  Payment Scheme Component of the next Payment Exchange Block.

The response message contains payment schema specific data if the continuation status signals "Continue". The IOTP Application Core is allowed to reissue this request several times on failed analyses of the response.

XML definition:

<!ELEMENT ResumePaymentPaymentHandlerResponse (PaySchemePackagedContent*) > <!ATTLIST ResumePaymentPaymentHandlerResponse

 ContStatus  (End|Continue)  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Continue Process

This API function passes one specific IOTP Payment Scheme Component, i.e., the encapsulated Packaged Content elements, received from the counter party (e.g., Consumer) to the IOTP Payment Bridge and responds with the next IOTP Payment Scheme Component for submission to the counter party.

Input Parameters

o Payty's Payment Identifier o Process (Transaction) Type which distinguishes between Payments

  and Inquiries.

o Wallet Identifier and/or Pass Phrase o (Payment Scheme) Packaged Content - copied from the Payment

  Scheme Component of the received Payment Exchange Block or from
  the Error Block.

Each party should set the payment identifier with the local identifier (Consumer: ConsumerPayId; Merchant: MerchantPayId; Payment Handler: PaymentHandlerPayId).

XML definition:

<!ELEMENT ContinueProcess (PaySchemePackagedContent+) > <!ATTLIST ContinueProcess

 PayId  CDATA  #REQUIRED
 ProcessType  (Payment | Inquiry) 'Payment'
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Continuation Status o (Payment Scheme) Packaged Content - for insertion in the

  Payment Scheme Component of the next Payment Exchange Block or
  final Payment Response Block

The response message contains payment schema data if the continuation status signals "Continue". The IOTP Payment Bridge must signal "End", if the payment scheme data was received within an IOTP Error Block containing an Error Component with severity HardError.

XML definition:

<!ELEMENT ContinueProcessResponse (PaySchemePackagedContent*) > <!ATTLIST ContinueProcessResponse

 ContStatus  (End|Continue)  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Change Process State

The IOTP Application Core changes the current payment status by this request. The IOTP Payment Bridge may be notified about business level normal termination, cancellation, suspension, and processing errors. Notification happens by requesting the intended process state.

The IOTP Payment Bridge processes the status change and reports the result.

The IOTP Application Core has to analyze any returned process status in order to check whether the IOTP Payment Bridge has agreed to or declined the status switch. E.g., the submitted Process State "CompleteOk" may lead to the Payment Status "Failed" if the payment transaction has already failed.

Transaction Suspension is notified by the newly introduced Process State "Suspended". The other attribute values have been taken from the IOTP specification.

This API function might be called by the Consumer, Merchant, or Payment Handler for each payment transaction anytime after the issuance of "FindPaymentInstrument" to the IOTP Payment Bridge by the Consumer, the issuance of "FindAcceptedPaymentBrand" by the Merchant, or the issuance of "StartPaymentPaymentHandler" by the Payment Handler.

The Process States "CompletedOk", "Failed", and "ProcessError" are final in the sense that they can not be changed on subsequent calls. However, the API function should not return with an error code if such an incompatible call has been issued. Instead it should report the old unchanged Process State.

Unknown payment transactions are reported by the Error Code "AttValInvalid" pointing to the PayId attribute.

Input Parameters

o Party's Payment Identifier o intended Payment Status o intended Completion Code o Process (Transaction) Type which distinguishes between Payments

  and Inquiries.

o Wallet Identifier and/or Pass Phrase

XML definition:

<!ELEMENT ChangeProcessState EMPTY > <!ATTLIST ChangeProcessState

 PayId  CDATA  #REQUIRED
 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)  #REQUIRED
 CompletionCode  NMTOKEN  #IMPLIED
 ProcessType  (Payment | Inquiry) 'Payment'
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Process State and Percent Complete o Completion Code o Status Description and its language annotation

XML definition:

<!ELEMENT ChangeProcessStateResponse EMPTY > <!ATTLIST ChangeProcessStateResponse

 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)  #REQUIRED
 PercentComplete  CDATA  #IMPLIED
 CompletionCode  NMTOKEN  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 StatusDesc  CDATA  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

General Inquiry API Calls

The following calls are not necessarily assigned to a payment transaction and may be issued at any time. There are no dependencies on any other calls.

Remove Payment Log

The IOTP Application Core notifies the IOTP Payment Bridge and/or the corresponding Existing Payment Software via IOTP Payment Bridge that any record in the Payment Log file, that deals with the listed payment transaction, might be removed.

Input Parameters

o Party's Payment Identifier o Wallet Identifier and/or Pass Phrase

XML definition:

<!ELEMENT RemovePaymentLog EMPTY > <!ATTLIST RemovePaymentLog

 PayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

XML definition:

<!ELEMENT RemovePaymentLogResponse EMPTY > <!ATTLIST RemovePaymentLogResponse >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Payment Instrument Inquiry

This API function retrieves the properties of the Payment Instrument. The Payment Instrument Identifier could be omitted if this identifier is derived by other means, e.g., by analysis of the currently inserted chip card. If the Payment instrument could not uniquely determined, the IOTP Payment Bridge may provide suitable dialogs for user input.

E.g., this API function might be used during problem resolution with the Customer Care Provider of the issuer of the payment instrument, in order to inquire payment instrument specific values.

Input parameters

o Brand Identifier o Payment Instrument Identifier o Protocol Identifier

o Wallet Identifier and/or Pass Phrase o Property Type List - sequence of values whose language is

  identified by xml:lang

o (Brand) PackagedContent Content - further payment brand

  description

o Protocol Brand Content - further payment brand information o (Protocol Amount) PackagedContent Content - further payment

  protocol description

o (Pay Protocol) PackagedContent Content - further payment

  protocol description

The codes in the property type list are of two types:

o generic codes which apply to all payment methods but might be

  unavailable

o Payment Brand specific codes.

Generic codes for the Property Type List are:

Property Type Meaning Balance Current balance Limit Maximum balance PaymentLimit Maximum payment transaction limit Expiration Expiration date Identifier Issuer assigned identifier of the payment

                     instrument.  Usually, it does not match with
                     the API's payment instrument identifier.

LogEntries Number of stored payment transaction

                     entries.  The entries are numbered from 0
                     (the most recent) to some non-negative
                     value for the oldest entry.

PayAmountn Payment Amount of the n-th recorded payment

                     transaction, n may negative

PayPartyn Remote party of the n-th payment recorded

                     transaction, n may negative

PayTimen Time of the n-th payment recorded

                     transaction, n may negative

XML definition:

<!ELEMENT PaymentInstrumentInquiry (BrandPackagedContent*,

 ProtocolBrand?,
 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*) >

<!ATTLIST PaymentInstrumentInquiry

 BrandId  CDATA  #REQUIRED
 PaymentInstrumentId  CDATA  #IMPLIED
 ProtocolId  CDATA  #REQUIRED
 PropertyTypeList  NMTOKENS  #REQUIRED
 xml:lang  NMTOKEN  #IMPLIED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output parameters

o a list of zero or more unavailable property values whose

  language are identified by xml:lang.

o a list of zero or more sets of "Properties Types", "Property

  Values" and "Property Descriptions"

XML definition:

<!ELEMENT PaymentInstrumentInquiryResponse

 (PaymentInstrumentProperty*) >

<!ATTLIST PaymentInstrumentInquiryResponse

 xml:lang  NMTOKEN  #REQUIRED
 UnavailablePropertyList NMTOKENS  #IMPLIED >

<!ELEMENT PaymentInstrumentProperty EMPTY > <!ATTLIST PaymentInstrumentProperty

 PropertyType  NMTOKEN  #REQUIRED
 PropertyValue  CDATA  #REQUIRED
 PropertyDesc  CDATA  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Inquire Pending Payment

This API function reports the party's payment identifiers of any pending payment transactions that the IOTP Payment Bridge/Existing Payment Software recommends be completed or suspended prior to the processing of new payment transactions. It does not respond with further transaction details. These have to be requested with "Inquire Process State".

Note that the IOTP Payment Bridge has to respond without the benefit of any pass phrase if there exist no pending payment transaction. But if there are some pending payment transactions, the IOTP Payment Bridge may refuse the immediate response and may instead request the appropriate pass phase from the IOTP Application Core.

Input Parameters

o Wallet Identifier and/or Passphrase

XML definition:

<!ELEMENT InquirePendingPayment EMPTY > <!ATTLIST InquirePendingPayment

 WalletId  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Party's Payment Identifier

XML definition:

<!ELEMENT InquirePendingPaymentResponse (PaymentId*) >

<!ELEMENT PaymentId EMPTY > <!ATTLIST PaymentId

 PayId  CDATA  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Payment Related Inquiry API Calls

Check Payment Receipt

This function is used by the Consumer and might be used by the Payment Handler to check the consistency, validity, and integrity of IOTP payment receipts which might consist of Packaged Content Elements

o from the IOTP Payment Receipt Component - provided by the Payment

  Handler's "Inquire Process State" API call shortly before payment
  completion,

o from Payment Scheme Components being exchanged during the actual

  payment, or

o being returned by the Consumer's "Inquire Process State" API call

  shortly before payment completion

The IOTP Application Core has to check the PayReceiptNameRefs attribute of the IOTP Payment Receipt Component and to supply exactly the Packaged Content Elements being referred to.

Failed verification is returns a business error.

Note that this Payment API assumes that any payment receipt builds upon a subset of elements with reference to [IOTP]. Furthermore, the Packaged Content Element have to be distinguishable by their Name attribute.

Input Parameters

o Party's Payment Identifier o Wallet Identifier and/or Pass Phrase o All Packaged Content Elements in the payment receipt

XML definition:

<!ELEMENT CheckPaymentReceipt (PackagedContent*) > <!ATTLIST CheckPaymentReceipt

 PayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

XML definition:

<!ELEMENT CheckPaymentReceiptResponse EMPTY > <!ATTLIST CheckPaymentReceiptResponse >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Expand Payment Receipt

This API function expands any IOTP payment receipt into a form which may be used for display or printing purposes. "Check Payment Receipt" should be used first if there is any question of the payment receipt containing errors.

The same conventions apply to the input parameter as for "Check Payment Receipt" (cf. Section 4.5.1).

Input Parameters

o Party's Payment Identifier o Wallet Identifier and/or Pass Phrase o All Packaged Content Elements that build the payment receipt

XML definition:

<!ELEMENT ExpandPaymentReceipt (PackagedContent*) > <!ATTLIST ExpandPaymentReceipt

 PayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Brand Identifier o Protocol specific Brand Identifier o Payment Instrument Identifier o Currency Code and Currency Code Type o Payment Amount o Payment Direction o Time Stamp - issuance of the receipt o Protocol Identifier o Protocol specific Transaction Identifier - this is an internal

  reference number which identifies the payment

o Consumer Description, Payment Handler Description, and a

  language annotation

o Style Sheet Net Location o Payment Property List. A list of type/value/description triples

  which contains additional information about the payment which
  is not covered by any of the other output parameters; property
  descriptions have to consider the language annotation.

The Style Sheet Net Location refers to a Style Sheet (e.g., [XSLT]) that contains presentation information about the reported XML encoded data.

XML definition:

<!ELEMENT ExpandPaymentReceiptResponse (PaymentProperty*) > <!ATTLIST ExpandPaymentReceiptResponse

 BrandId  CDATA  #IMPLIED
 PaymentInstrumentId  CDATA  #IMPLIED
 Amount  CDATA  #IMPLIED
 CurrCodeType  NMTOKEN  #IMPLIED
 CurrCode  CDATA  #IMPLIED
 PayDirection  (Debit|Credit)  #IMPLIED
 TimeStamp  CDATA  #IMPLIED
 ProtocolId  CDATA  #IMPLIED
 ProtocolBrandId  CDATA  #IMPLIED
 ProtocolTransId  CDATA  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 ConsumerDesc  CDATA  #IMPLIED
 PaymentHandlerDesc  CDATA  #IMPLIED
 StyleSheetNetLocn  CDATA  #IMPLIED>

<!ELEMENT PaymentProperty EMPTY > <!ATTLIST PaymentProperty

 PropertyType  NMTOKEN  #REQUIRED
 PropertyValue  CDATA  #REQUIRED
 PropertyDesc  CDATA  #REQUIRED >

The Existing Payment Software should return as many attributes as possible from the supplied IOTP Payment Receipt. The payment supplement defines the attribute values for the payment properties.

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Inquire Process State

This API function returns the current payment state and optionally further Packaged Content Elements that form the payment receipt. Called by the Payment Handler, the IOTP Payment Bridge might respond with data intended for inclusion in the IOTP Payment Receipt Component's Packaged Content. When the Consumer calls this function shortly before payment completion, it may respond with further items of the payment receipt. Such items might be created by a chip card.

Input Parameters

o Party's Payment Identifier o Wallet Identifier and/or Pass Phrase

XML definition:

<!ELEMENT InquireProcessState EMPTY > <!ATTLIST InquireProcessState

 PayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Current Process State and Percent Complete o Completion Code o Status Description and its language annotation o Payment Receipt Name References to all Packaged Content

  Elements that build the payment receipt (cf. Section 4.5.1),
  even if they have not been created so far (Consumer's share)

o Any Packaged Content Element being available that form the

  payment receipt

The IOTP provides a linking capability to the payment receipt delivery. Instead of encapsulating the whole payment specific data into the packaged content of the payment receipt, other Payment Scheme Components' Packaged Content might be referred to.

XML definition:

<!ELEMENT InquireProcessStateResponse (PackagedContent*) > <!ATTLIST InquireProcessStateResponse

 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)  #REQUIRED
 PercentComplete  CDATA  #IMPLIED
 CompletionCode  NMTOKEN  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 StatusDesc  CDATA  #IMPLIED
 PayReceiptNameRefs  NMTOKENS  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Start Payment Inquiry

This API function responds with any additional payment scheme specific data that is needed by the Payment Handler for Consumer initiated payment transaction inquiry processing. Probably, the IOTP Payment Bridge (or the corresponding Existing Payment Software) has to determine the payment related items that were provided with the "Start Payment Consumer" API function call.

Input Parameters

o Consumer Payment Identifier o Wallet Identifier and/or Pass Phrase

XML definition:

<!ELEMENT StartPaymentInquiry EMPTY > <!ATTLIST StartPaymentInquiry

 ConsumerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o (Payment Scheme) Packaged Content - intended for insertion in

  the Payment Scheme Component of  the Inquiry Request Block

XML definition:

<!ELEMENT StartPaymentInquiryResponse

 (PaySchemePackagedContent*) >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Inquire Payment Status

The Payment Handler calls this API function for Consumer initiated inquiry processing. It differs from the previous "Inquire Process State" API function by the optional inclusion of payment scheme specific data. The response may encapsulate further details about the payment transaction.

Input Parameters

o Payment Handler Payment Identifier o Wallet Identifier and/or Pass Phrase o (Payment Scheme) Packaged Content - copied from the Inquiry

  Request Block's Payment Scheme Component

XML definition:

<!ELEMENT InquirePaymentStatus (PaySchemePackagedContent*) > <!ATTLIST InquirePaymentStatus

 PaymentHandlerPayId  CDATA  #REQUIRED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o Current Process State o Completion Code

o Status Description and its language annotation o (Payment Scheme) Packaged Content - intended for insertion in

  the Payment Scheme Component of the Inquiry Response Block

XML definition:

<!ELEMENT InquirePaymentStatusResponse (PaySchemePackagedContent*) > <!ATTLIST InquirePaymentStatusResponse

 PaymentHandlerPayId  CDATA  #REQUIRED
 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)  #REQUIRED
 CompletionCode  NMTOKEN  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 StatusDesc  CDATA  #IMPLIED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Other API Calls

Manage Payment Software

The following API function notifies the IOTP Payment Bridge about the intended registration, modification, or deletion of a payment instrument. The actual processing is up to the IOTP Payment Bridge.

This API request may also be used to activate the IOTP Payment Bridge (and the corresponding Existing Payment Software) for general administration purposes.

Input Parameters

o Brand Identifier o Protocol Identifier o Any action code: o New - add new payment method / instrument o Update - change the payment method's / instrument's data o Delete - delete a payment method / instrument o Wallet Identifier and/or Pass Phrase o (Brand) Packaged Content - further payment brand description o (Pay Protocol) Packaged Content - further payment protocol

  description

o (Protocol Amount) Packaged Content - further payment protocol

  description

If the Action attribute is set, the Brand and Protocol Identifier have to also be set. The IOTP Payment Bridge has to provide the required user dialogs and selection mechanisms. E.g., updates and deletions may require the selection of the payment instrument. A new wallet might be silently generated on the supplement of a new Wallet Identifier or after an additional end user acknowledge. The IOTP Application Core should not provide any pass phrases for new wallets. Instead, the IOTP Payment Bridge has to request and verify them, which may return their value to the IOTP Application Core in plain text. In addition, the IOTP Payment Bridge returns the supported authentication algorithms when a new brand and protocol pair has been registered.

If the "Action" attribute is omitted, the IOTP Payment Bridge which is responsible for the Existing Payment Software pops up in a general interactive mode.

XML definition:

<!ELEMENT ManagePaymentSoftware (BrandPackagedContent*,

 ProtocolAmountPackagedContent*,
 PayProtocolPackagedContent*) >

<!ATTLIST ManagePaymentSoftware

 BrandId  CDATA  #IMPLIED
 ProtocolId  CDATA  #IMPLIED
 Action  (New |
  Update |
  Delete)  #IMPLIED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED >

Output Parameters

o An action code: o New - added new wallet o Update - changed wallet's configuration o Delete - removed a wallet o Wallet Identifier and/or Pass Phrase

The IOTP Payment Bridge does not return any information about the set of registered payment instruments because these data items are dynamically inferred during the brand selection process at the beginning of each IOTP transaction. However, the IOTP Application Core has to be notified about new wallets and should be notified about updated and removed wallets (identifier). Alternatively,

removed wallets can be implicitly detected during the next brand selection phase. Updated wallets do no affect the processing of the IOTP Application Core. The IOTP Payment Bridge should only support the addition of at most one wallet because it is not able to report multiple additions at once back to the IOTP Application Core.

XML definition:

<!ELEMENT ManagePaymentSoftwareResponse EMPTY > <!ATTLIST ManagePaymentSoftwareResponse

 Action  (New |
  Update |
  Delete)  #IMPLIED
 WalletID  CDATA  #IMPLIED
 Passphrase  CDATA  #IMPLIED
 AuthNames  NMTOKENS  #REQUIRED >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Call Back Function

This API function, called by the IOTP Payment Bridge, is used to provide information for Consumer or Payment Handler notification about the progress of the payment transaction.

Its use is illustrated in the diagram below.

  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
                     IOTP Application   ----calls----
                     |     Core     |               |
      display        |              |               v
        to  <----------  Call Back <--calls---  Payment
       user          |              |           Software
                     ----------------
  • +*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*
                   Figure 9.  Call Back Function

Whenever this function is called, the content of the status description should be made available to the user. For example on a status bar, a pop up window, etc.

A reference to the Call Back function is passed as an input parameter to the "Start Payment X" and "Resume Payment X" API function. Afterwards, this function might be called whenever the status changes or progress needs to be reported.

Input Parameters

o the software identifier of the caller o Party's Payment Identifier o Process State and Percent Complete o Completion Code o Status Description and its language annotation, text which

  provides information about the progress of the call.  It should be
  displayed or made available to, for example, the Consumer.

Examples of Status Description could be:

o "Paying 12.30 USD to XYZ Inc" o "Payment completed" o "Payment aborted"

The valid languages are announced in the Call Back Language List attribute in "Start Payment X" and "Resume Payment X" API function calls.

XML definition:

<!ELEMENT CallBack EMPTY > <!ATTLIST CallBack

 ContentSoftwareID  CDATA  #IMPLIED
 PayId CDATA #REQUIRED
 ProcessState  (NotYetStarted |
  InProgress |
  Suspended |
  CompletedOk |
  Failed |
  ProcessError)  #IMPLIED
 PercentComplete  CDATA  #IMPLIED
 CompletionCode  NMTOKEN  #IMPLIED
 xml:lang  NMTOKEN  #IMPLIED
 StatusDesc  CDATA  #IMPLIED >

Output Parameters

XML definition:

<!ELEMENT CallBackResponse EMPTY > <!ATTLIST CallBackResponse >

Tables 4 and 5 explain the attributes and elements; Table 3 introduces the Error Codes.

Basically, the call back function accepts all input arguments or rejects the whole request. It may even accept malformed requests.

Some payment schemes may support or require that the Consumer might be able to cancel the payment at any time. The Call Back function can be used to facilitate this by returning the cancellation request on the next call (using the Business Error Code and Completion Code "ConsCancelled").

Vice versa the Payment Handler's Application Core might use the similar mechanism to signal its IOTP Payment Bridges any exceptional need for a fast shutdown. These IOTP Payment Bridges may initiate the appropriate steps for terminating/cancelling all pending payment transactions.

Note that the "Change Process State" API function provides the second mechanism for such kind of notification. Therefore, the IOTP Payment Bridge or Existing Payment Software may ignore the details of the "Call Back" response.

Security Consideration

The IOTP Payment APIs only supports security using pass phrase to access to payment Wallet. These can be protected over TLS, which provides stronger security at the transport layer, but implementations are out the scope of this document.

See also security consideration section of [IOTP].

References

Normative References

[IOTP] Burdett, D., "Internet Open Trading Protocol - IOTP

          version 1.0", RFC 2801, April 2000.

[ISO4217] ISO 4217: Codes for the Representation of Currencies.

          Available from ANSI or ISO.

[URL] Berners-Lee, T., Masinter, L. and M. McCahill, "Uniform

          Resource Locators (URL)", RFC 1738, December 1994.

[UTC] Universal Time Coordinated. A method of defining time

          absolutely relative to Greenwich Mean Time (GMT).
          Typically of the form: "CCYY-MM- DDTHH:MM:SS.sssZ+n" where
          the "+n" defines the number of hours from GMT. See ISO
          DIS8601.

[XML] Extensible Mark Up Language (XML) 1.0 (Third Edition). A

          W3C recommendation. See http://www.w3.org/TR/REC-xml

[XML-NS] Namespaces in XML Recommendation. T. Bray, D. Hollander,

          A. Layman. Janaury 1999.  http://www.w3.org/TR/REC-xml-
          names

[XSLT] Extensible Style Language Transformations 1.0, November

          1999, See http://www.w3.org/TR/xslt

Informative References

[IOTPBOOK] D. Burdett, D.E. Eastlake III, and M. Goncalves, Internet

          Open Trading Protocol, McGraw-Hill, 2000. ISBN 0-07-
          135501-4.

[SET] SET Secure Electronic Transaction(TM) , Version 1.0, May

          31, 1997
          Book 1: Business Description
          Book 2: Programmer's Guide
          Book 3: Formal Protocol Definition

[SET/IOTP] Kawatsura, Y., "Secure Electronic Transaction (SET)

          Supplement for the v1.0 Internet Open Trading Protocol
          (IOTP)", RFC 3538, June 2003.

[TLS] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",

          RFC 2246, January 1999.

Acknowledgement

The contributions of Werner Hans of Atos Origin are gratefully acknowledged.

Authors' Addresses

Hans-Bernhard Beykirch

EMail: [email protected]

Yoshiaki Kawatsura Hitachi, Ltd. 890 Kashimada Saiwai-ku Kawasaki-shi Kanagawa, Japan 212-8567

EMail: [email protected]

Masaaki Hiroya Technoinfo Service, Inc. 333-2-718 Uchikoshi-machi Hachioji-shi Tokyo 192-0911 JAPAN

EMail: [email protected]

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