2025-02-10 AnonCreds Working Group Meeting

Summary

Time: 15:00 Pacific / 16:00 Mountain / Super Late Central Europe (Midnight...) / 12:00 Auckland and Wellington

Call Link: https://zoom.us/j/97954159540?pwd=WWk3WmQ3MVh1SXBYZGVreGl0QllGdz09

Recording:

Notices: 

This specification creating group operates under the Linux Foundation Community Specification License v1.0.

Meeting Attendees

• @Stephen Curran (BC Gov / Cloud Compass Computing Inc.) <swcurran@cloudcompass.ca>

Related Specifications and Repositories:

• AnonCreds v1.0:

  • The v1.0 specification is published here: https://hyperledger.github.io/anoncreds-spec/

  • The Working Group uses this GitHub repository to manage the specification: https://github.com/hyperledger/anoncreds-spec

  • The AnonCreds Methods Registry: https://hyperledger.github.io/anoncreds-methods-registry

  • The v1.0 implementation in Rust is here: https://github.com/hyperledger/anoncreds-rs

  • The v1.0 implementation is dependent on this Rust CL Signatures implementation: https://github.com/hyperledger/anoncreds-clsignatures-rs

• AnonCreds v2.0

  • The initial framework for the v2.0 specification repository is here: https://github.com/hyperledger/anoncreds-spec-v2

  • The v2.0 implementation in Rust is here: https://github.com/hyperledger/anoncreds-v2-rs

  • Underlying AnonCreds v2.0 are cryptographic libraries in Hyperledger Labs Agora

Meeting Preliminaries:

• Welcome and Introductions

• Announcements:

  • Next Meeting – Monday, February 24 will be at this time – 7:00 Pacific / 16:00 Central Europe vs. the usual 15:00 Pacific / Midnight Central Europe time.

• Any updates to the Agenda?

Agenda

• BBS Support for AnonCreds v2 

  • Other issues to go. – verify alignment with the IETF draft – documenting what options are used/not used, design choices) parallel tests – PS and BBS

• Webinar AnonCreds v2 and "AnonCredsBBS"

  • Draft Agenda:

    • AnonCreds v2 – introduction

    • Capabilities – ZKP features

    • Signature Scheme support – Pluggable, with BBS and PS Signatures implemented. Hint at PQ.

    • Details of the BBS Support – alignment with the IETF CFRG draft (BBS Signatures, BBS Blind Signatures, BBS pseudonymous identifiers)

    • Scalable Revocation

    • Next Steps

  • Timing?  Mid-march

• Presentation and demo to conclude the Revocation Manager Project - a Hyperledger Mentorship Program project.

• The did:webvh AnonCreds Method – https://hackmd.io/9cQkOktoSSeXxRiU5eWtaA?both

  • Publishing, resolving and verifying AnonCreds objects for a did:webvh DID

  • Mostly easy: did:webvh:<scid>:example.com/AnonCreds/schema/<name/<version>/<hash>

    • Attested Resources – using the hash of the resource placed in the identifier, and an attached Data Integrity proof.

    • Resolvable Identifiers are put into objects:

      • Schema identifier in CredDef

      • CredDef identifier in Verifiable Credential and Verifiable Presentation.

      • RevReg identifier in Verifiable Credential

    • Tricky – RevRegEntry (state of RevReg) have associated timestamps, and have to be "discovered" by the Holder, with the timestamp conveyed to the Verifier.

    • Solution:

      • RevRegDef has an updated list of RevRegEntry [timestamp, identifier] pairs in the Attested Resource, but outside of the RevRegDef resource itself.

        • Hash of the RevRegDef is consistent.

        • Proof is update each time the list is extended.

      • RevRegEntry is "just another" Attested Resource

      • Holder gets RevRegDef and finds timestamp (and hence, the identifier) for a RevRegEntry useful to satisfy the Presentation Request.

      • Verifier gets RevRegDef and finds the timestamp (and the identifier) for the RevRegEntry used by the Holder in the Presentation.

      • Both resolve the RevRegEntry identifier selected to get the actual RevRegEntry state (`[timestamp, state of each verifiable credential, accumulator]`).

  • Spec PR has been created and will be published beside the did:webvh spec (https://identity.foundation/didwebvh/), added to the info site (https://didwebvh.info).

  • Reference to the spec will be added to the AnonCreds DID Methods Registry – https://hyperledger.github.io/anoncreds-methods-registry/

  • Mike's comment about Provenance Logs – link to spec: https://github.com/cryptidtech/provenance-specifications/blob/main/specifications/provenance-logs.md

• Open Discussion

To Dos:

Action items