2023-01-23 AnonCreds Specification Working Group Meeting

Owned by Stephen Curran
Last updated: Jan 23, 2023
3 min read

Summary

  • PRs
  • issuance_by_* handling
  • Revocation Interval
  • Do we need an anoncreds-indy-rs repo for the legacy indy and did:indy AnonCreds methods?
  • Progress on the anoncreds_rs implementation
  • Open Discussion

Recording of Call: dummyfile.txt

Notices: 

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Meeting Attendees

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

Rodolfo Miranda (RootsID)<rodolfo.miranda@rootsid.com>

Matteo Midena  (Monokee) <matteo.midena@monokee.com>

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


Related Repositories:

Meeting Preliminaries:

  • Welcome and Introductions
  • Announcements:
    • Request for a host for the meeting next week – Timo
  • Updates the Agenda

Agenda

Open Issue

  • PRs for review and merging
    • Prover DID PR needs more work. From Berend: The prover_id gets hashed with, optionally, the revocation index in there as well
  • Issues to Discuss
    • issuance_by_* handling
    • Revocation Interval
      • To set "validation" to true/false based on the RevRegEntry timestamp in relation to the revocation interval?  Presentation 
      • Key points:
        • 1. an RevRegEntry is “current” from the time it is written, to the time of the next RevRegEntry
        • 2. “within the interval” is based on when a RevRegEntry is “current” (see 1.), not its timestamp.
        • 3. AnonCreds should calculate “within interval” (using 2.) and mark verification true if the RevRegEntry used by the Prover is within the interval, else false.
          • However, this is different than what is done today – which is to just return the status of the Non-Revocation Proof based on whatever RevRegEntry/timestamp the Holder used.
          • Danger:
            • False-Negatives: If a strict "timestamp used is between from, to" and not based on when a RevReg is "current" (per 2.), we will get "not verified" incorrectly.
            • False-Positives: If we don't do any checking of the timestamp and the interval, the holder could incorrectly use an old RevRegEntry.
        • 4. General point: AnonCreds should return both a summary (true/false) and if false, additional data about why it was false.
      • Next steps:
        • Consider options and discuss again next week.
    • Issue #137 added regarding further investigation into what happens to the issuance data flow nonce(s) by Belsy
  • Do we need an anoncreds-indy-rs repo for the legacy indy and did:indy AnonCreds methods?
    • Briefly discussed.
    • Decision: No extra repo is needed. An Aries (or other tech stack) implementation (e.g., ACA-Py, AFJ) should implement the AnonCreds methods required.
      • Likely we need more discussion of this, and to put this into spec.
  • Checkin: anoncreds-rs implementation progress, requests
  • Open Discussion

Future Calls

To Dos:

  • Backwards Compatibility
    • PRs in (#82, #105) that seem to change public data structures – ones that are handled outside of AnonCreds and/or by two or more participants (issuer, holder, verifier)
    • We want to retain compatibility with existing data – credentials that have been issued and the published AnonCreds objects on which they rely.
    • That extends to business logic – e.g. the handling of the objects not just by AnonCreds, AnonCreds Methods and Aries Frameworks, but also by business applications built on Aries.
    • Suggestion:
      • Include in the specification a statement about backward compatibility
        • Perhaps this is what Ankur had planned to do?
      • Formalize what data structures will be expected by AnonCreds
        • This is being done throughout the specification and verified against the current implementation.
      • As needed support sending and receiving data in "old" and "new" formats, but (for now) always sending "old" formats.
        • TBD if there are any such cases.

Action items