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2022-11-07 AnonCreds Specification Working Group Meeting

2022-11-07 AnonCreds Specification Working Group Meeting

Nov 07, 2022

Summary

  • Logos!

  • Transition to Hyperledger

  • RevReg Objects between AnonCreds and AnonCreds Methods

  • Iterations on AnonCreds in W3C VC Standard format

  • Open Issues and PRs

  • Open Discussion

Recording of Call: 

Notices: 

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

Hyperledger is committed to creating a safe and welcoming

community for all. For more information

please visit the Hyperledger Code of Conduct.

Welcome and Introductions

Attendees

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

@Timo Glastra (Animo Solutions) <timo@animo.id>

@Lance Byrd (RootsID) <lance.byrd@rootsid.com>

Related Repositories:

Meeting Preliminaries:

  • Welcome and Introductions

  • Announcements:

    • IIW -- Nov 15-17, Mountain View, Calif.

      • Suggestions for what to do at IIW

        • Ledger-agnostic AnonCreds

        • AnonCreds in W3C Format

        • Sam:

          • Governance, Aries for other than AnonCreds

  • Updates the Agenda

Agenda 

  • Logos – selecting the Hyperledger AnonCreds project logo. Link to survey.

    • Finalize - Concept 1, colors TBD (likely Greens 7 votes vs. 4 for each of Blues and Red/Grey)

    • Sent to Hyperledger and the designer

  • Transition into Hyperledger AnonCreds

    • Tasks in moving this group into Hyperledger

    • Move the repos from AnonCreds-WG organizations into HL, get new URL https://hyperledger.github.io/anoncreds-spec/

    • Create new replacement repos in existing organization and publish a redirector to the new location - https://anoncreds-wg.github.io/anoncreds-spec/

    • PR to update the references to the home of the specifications as being in Hyperledger and update the Community License V1.0 documents.

    • Create a Meetings page off the Hyperledger AnonCreds home page

    • Move all meeting agendas to the new Meetings page

    • All the other work in establishing the Hyperledger AnonCreds project: Checklist

  • RevReg Object updates -- enabling AnonCreds Methods to support both deltas and "full state" RevReg storage @Timo Glastra

    • Discussion starts at 18:49 of the recording. 

    • Initial proposed revocation list data model: https://hackmd.io/@animo/Sys3SqUri

    • In short – in creating the presentation, the invoking process must pass an object with this structure, plus (at least) the tails file:

      • { "revocation_list": [0,1,0,1....], "current_accumulator": "xxx", "timestamp": "xxx" }

      • That will enable the AnonCreds presentation generator to produce the Proof of Non Revocation.

      • The invoker must get from the AnonCreds Method the data in that format, regardless of how the data is stored on ledger.

    • Next step is to put this into the specification as part of the presentation section – assigned to Stephen Curran to write (he should get on it...Soon!!)

  • Creating/sharing AnonCreds verifiable credential and presentation objects in W3C VC Data Model format

  • Open PRs Review, Open Issues Review

    • Issue #86: Should we allow the possibility of an Issuer using only a subset of a schema?

      • Discussed at the 37:26 mark of the recording.

      • Short answer is no – it's a bad idea for holders and verifiers, as it eliminates the expectation of what claims are in a credential. As noted in the ACA-Py discussion, the issuer has options for not using attributes (such as putting "NULL" into the credential). Such a change would be very complicated.

    • Issue #92: Does AnonCreds support in the Presentation Request / Presentation flow the concept of presenting any one of N verifiable credentials?

      • Discussed at the 47:04 mark of the recording. 

      • It may, using unrevealed attributes.

      • If it does not work, the path to follow to "fix" this would mostly likely be to go to DIF Presentation Exchange, and not to 

    • Issue #100: Clarifying if the holder is the software agent acting on behalf of an entity or the entity itself

      • Request for others to review and discuss at the next meeting

  • Open Discussion

Future Calls

  • None pending

To Dos:

  • Request from Stephen Curran -- I'd like to go through the presentation section of the spec to convert the specific implementation calls (e.g. indy_prover_... and the like) into content to be more about the data objects passed into AnonCreds/returned from AnonCreds for processing events.

  • Ankur to add paragraph about philosophy of the AnonCreds API, styles

  • Review the Issuing and Presentation sections to exclude Legacy Indy impacts, and to formalize the Abstract API for writing/reading published objects

  • Cred Def Generation + PRIVATE_CRED_DEF -- non revocation, and plus revocation

  • Revocation data elements -- definition

  • Normative/Non-normative references

    • Collect from documents mentioned below (under action items) and from previous meeting

Action items