The purpose of this document is to outline a coherent implementation and deployment strategy for the Web Payments standardization work at W3C.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document is a work in progress and is being released early and often using an agile process; it is incomplete.

This document was published by the Web Payments Interest Group as an Editor's Draft. If you wish to make comments regarding this document, please send them to public-webpayments-comments@w3.org (subscribe, archives). All comments are welcome.

Publication as an Editor's Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 1 August 2014 W3C Process Document.

Table of Contents

1. Introduction

The purpose of this document is to outline a coherent implementation and deployment strategy for the Web Payments standardization work at W3C. It consists of the following major sections:

1.1 Relationship to Other Documents

This document is one part of a greater body of work around Web Payments that the Web Payments Interest Group at W3C is producing. These other documents include:

2. Terminology

This document attempts to communicate the concepts outlined in the Web Payments space by using specific terms to discuss particular concepts. This terminology is included below and linked to throughout the document to aid the reader:

A person, organization, or software agent that is capable of interacting with the world.
An entity that receives funds as required by a transaction.
An entity that provides a source of funds as required by a transaction.
payment instrument
A mechanism used to transfer value from a payer to a payee. Examples: Corporate Visa card, personal Visa card, a bitcoin account, a PayPal account, and an Alipay account. [PSD2] any personalized device(s) and/or set of procedures agreed between the payment service user and the payment service provider and used in order to initiate a payment order. [ECB] a tool or a set of procedures enabling the transfer of funds from a payer to a payee.
payment processor
An entity that submits and processes payments using a particular payment instrument to a payment network. Examples: Stripe, PayPal, Authorize.net, Atos, FedACH.
payment scheme
Sets of rules and technical standards for the execution of payment transactions that have to be followed by adhering entities (payment processors, payers and payees). Examples: Visa, MasterCard, Bitcoin, Ripple, PayPal, Google Pay, Alipay, Yandex money, ACH, SEPA. [ECB] a set of interbank rules, practices and standards necessary for the functioning of payment services.
An economic exchange between a payer and one or more payees. An agreement, communication, or movement carried out between a buyer and a seller to exchange an asset for payment.
transfer order
[ECB] an order or message requesting the transfer of assets (e.g. funds, securities, other financial instruments or commodities) from the debtor to the creditor.
a software service, providing similar functions in the digital world to those provided by a physical wallet, namely:
  • It holds payment instruments registered by the wallet owner;
  • It supports certain payment schemes and enables the payer to use registered payment instruments to execute a payment in accordance with that scheme;
  • It may hold one or more balances of some digital asset that can be used to make payments.
This definition of wallet may expand in the future to include other items people find in physical wallets such as digital receipts, coupons, and identification.

3. Coordination

In order for the Web Payments Activity to succeed, multiple groups will need to coordinate work in key areas related to payments, commerce, identity/credentials, and security. The diagram below outlines the categories that each group will participate in as well as the phases the groups will be active in:

4. Web Payments Phase 1

The initial implementation of the Web Payments work will start in October 2015 and will focus on delivering standards for a Minimum Viable Platform (MVP) by December 2017.

4.1 Goals

The scope of work supports the following elements of a basic purchase triggered by user interaction with a Web application initiating a new payment. These standards define a high-level message flow for a payment from payer to payee either in the form of a credit push (payer initiated) or a debit pull (payee initiated) payment, and can be used to facilitate a payment from any payment scheme.

Web Payments Basic Payment Flow
  • Registration, by the payer with their wallet, of any conforming payment instrument they wish to use on the Web (e.g. a credit or debit card, electronic cash, cryptocurrency, etc).
Negotiation of Terms
  • Payment Initiation Request, by the payee to the payer providing the terms of the payment including elements such as the accepted payment schemes, price, currency, recurrence, transaction type (purchase, refund etc.), timeout and requests for any additional data that is required from the payee.
Negotiation of Payment Instruments
  • Discovery, by the payer, of their available payment instruments that can be used to make the payment. This is done by matching those registered by the payer with those supported by the payee (as defined in the Payment Initiation Request), while keeping information local to the payer.
  • Selection of a payment instrument by the payer, confirmation of the terms, and sending of any requested data back to the payee for validation.
Payment Processing and Completion
  • Execution of the payment by either payer or payee.
  • Delivery of a Payment Completion generated by the entity that executed the payment. This may contain a Proof of Payment if supported by the payment scheme.

The group will also address exceptions that may occur during these steps, including payment authorization failure.

4.2 Use Cases

The following use cases are in scope for phase 1 with specific limitations expressed beside each use case:

Use Case Notes
One Time Payment
Ubiquitous Schemes
Discovery Unclear about how much wallet/payment instrument discovery flexibility should be in phase 1.
Payer Privacy The use case where the payer shares a subset of their payment instruments with the payee before the purchase is not in scope for this phase.
Manual Selection
Password Authentication
Multifactor Authentication Stretch goal for phase 1 with a focus on FIDO-based authentication and mobile phone-based fingerprint authentication.
Proofs Very basic proof of initiation of funds transfer for phase 1.
Virtual Goods
Physical Goods
Electronic Receipts Very basic receipt container and delivery protocol for phase 1.
Subscription Stretch goal for phase 1.
Basic Refund Stretch goal for phase 1.

The capabilities associated with each use case listed above can be found in the Web Payments Capabilities 1.0 document.

4.3 Groups and Scope

A list of relevant groups that will participate in the first iteration of specification creation.

Group Scope Charter
Web Payments Interest Group Continued development of use cases and requirements for phase 2. Liason between larger W3C community and other relevant standards bodies. October 2014 - December 2017
Web Payments Working Group Invoking a payment request, selecting a payment instrument, initiating funds transfer, delivering a proof of payment. Draft Charter
Web Authentication Working Group Secure authentication of entities (users, systems and devices) to enable high-security Web applications. Based on FIDO Alliance work. No charter yet
Hardware-based Security Working Group A set of Hardware-Based Web Security standard services providing Web Applications usage of secure services enabled by hardware modules (Trusted Execution Environments, Secure Elements, and other secure enablers). No charter yet.
Issue 1

It is currently unknown whether or not a Credentials WG or Linked Data Security WG will be created.

  • Related W3C Groups
    • Technical Architecture Group (TAG) (for reviews related to Web Architecture)
    • Security IG (for reviews about security)
    • Privacy IG (for reviews about sharing of sensitive information)
  • Related W3C Community Groups
    • Credentials
    • Web NFC
    • Web Payments
    • Web Bluetooth
    • Web Crypto API
    • Web of Things
  • 4.4 Deployment and Adoption

    Deployment in phase 1 will focus on enabling a few major online retailers to run Web Payment agents to issue Web Payment invoices for processing at 1-2 major online Payment Service Providers (or banks). The payment institutions would then initiate the payment and send a proof of payment back to the retailer.

    4.4.1 Goals

    • 3 major online retailers launching Web Payments support (for example: Alibaba, Walmart, Target, Best Buy, Overstock.com, Amazon, Tesco, eBay, etc.)
    • 1-2 large online payment companies (or banks) launching Web Payments support (for example: Google Wallet, PayPal, Alipay, Bank of America, HSBC, US Fed, etc.)
    • 5-10 smaller players from the online retail space and the payments space
    • 1 million payments within the first year after standardization
    • Favorable reviews by the Web developer community

    4.4.2 Strategies

    • Deployment strategy should be a pure software deployment. Do not require new hardware to be deployed.
    • Specifications should focus on technology that has already been prototyped.
    • All software should be cloud-only for phase 1. For example, do not try to support both cloud and local wallets due to a possible conflict around the "payment message bus" being implemented at the OS layer or the browser layer.

    4.5 Unresolved Issues

    Issue 2

    Where we need an extensible message format, we will want to specify at least a data model. The hard question will be whether we can achieve a single serialization (e.g., JSON or JSON-LD or XML) or whether we need multiple.

    Issue 3

    What canonicalization (if any) is needed in our messages for the purpose of digital signatures.

    A. Acknowledgements

    The editors wish to thank the participants of the Web Payments Interest Group for discussions about and contributions to this document, as well as the Web Payments Community Group for earlier work that informed this document.

    B. References

    B.1 Informative references

    Adrian Hope-Bailie; Ian Jacobs et al. A Vision for a Web Payments Architecture. W3C Note. URL: http://www.w3.org/Payments/IG/Vision