anoncreds-spec-v2

Scope

This document outlines the scope of work undertaken by the AnonCreds Open Specification Working Group.

Objectives

The objective of this Working Group is to document the AnonCreds v2.0 Specification. The goal of AnonCreds v2.0 is to retain and extend the privacy-preserving features of AnonCreds v1.0, while improving capabilities, performance, extensibility, and security.

v1.0

The AnonCreds v1.0 Specification provides, as a main difference to v0.1, the decoupling from the Indy ledger. It aims at being entirely ledger-agnostic. Non-goals of this version are changes to the CL signatures signing algorithm in the sense that this will remain the single supported cryptographic signature suite.

Background/Context

Since 2017, many organizations across the globe have been implementing verifiable credential-based solutions using the AnonCreds (Anonymous Credentials) implementation that was built into the Hyperledger Indy open source project. AnonCreds provides capabilities that many see as important for digital identity use cases in particular, and verifiable data in general. These features include:

While AnonCreds is open source and has become a de facto standard, it is not an open specification. Some in the larger self-sovereign identity community view AnonCreds as proprietary. Others are concerned that it is only open source, and subject to change by any code maintainer. The focus of this Working Group is to make AnonCreds an open specification and remove those barriers to broader adoption. As well, unsuccessful attempts have been made to align AnonCreds with the W3C Verifiable Credential Data Model v1.x, larger because of some core differences in the two approaches to verifiable credentials.

Initial work of the group will focus on putting into specification form the existing implementation of AnonCreds as found in the two existing Indy implementations. Part of that work will be the removal of all dependencies in the specification on the remote storage of objects, including Hyperledger Indy ledger. There is no technical requirement to require Indy in implementing AnonCreds, although there may be some identifiers that may have to be renamed because of Indy-isms in the identifiers.

Subsequent work will be on a new AnonCreds specification that has the goal of keeping the capabilities of the current AnonCreds, while updating the underlying primitives, such as replacing CL-Signatures with BBS+ Signatures and defining a more scalable revocation scheme. To be determined by the working group is whether and how the standard might produce artifacts that align with the in-process W3C VC v2.0 data model standard.

Membership and Joining

This specification is being developed under the Community Specification 1.0 License. Contributors to this specification must adhere to the license, as outlined in the repository’s license file file.

Deliverables

  1. The AnonCreds Specification v2.0. The goal of AnonCreds v2.0 is to retain and extend the privacy-preserving features of AnonCreds v1.0, while improving capabilities, performance, extensibility, and security.

Milestones

Key milestones will include, but are not limited to:

  1. Publication of the first Draft AnonCreds v2.0 Deliverable from a generated GitHub repository.
  2. Publication of the final Draft AnonCreds v2.0 Deliverable.
  3. Approval of the Draft AnonCreds v2.0 Deliverable as a Working Group Approved Deliverable.
  4. The placement of the AnonCreds v2.0 Specification on the standards track of an SDO.

Dependencies

Meeting Schedule and Notes

Meetings of the V2.0 Working Group are held weekly on Mondays at 10:00 Pacific / 19:00 Central Europe (except for time change mismatches). Meeting details, agendas, notes and links to the recordings are posted here.

Mailing List and Communications

This task force uses the following for communications

About This Document

Include in this document a detailed description of this Working Group’s Scope. This Scope is important is it establishes the bounds of each contributor’s and licensee’s patent commitment. For guidance on drafting an appropriate Scope, you may find ISO’s guidance (see page 5) helpful.

Any changes of Scope are not retroactive.