2023-01-30 AnonCreds Specification Working Group Meeting

Owned by Stephen Curran
Last updated: Jan 30, 2023
3 min read

Summary

  • Revocation Interval
  • Getting started on AnonCreds v2 Discussion?
  • Progress on the anoncreds_rs implementation
  • Open Discussion

Recording of Call: dummyfile.txt

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Meeting Attendees

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

Steve McCown (Anonyome Labs) <smccown@anonyome.com>


Related Repositories:

Meeting Preliminaries:

  • Welcome and Introductions
  • Announcements:
  • Updates the Agenda

Agenda

Open Issue

  • PRs for review and merging
  • Issues to Discuss
    • Revocation Interval
      • Approach to determine if the holder used an acceptable RevRegistry – see this Issue comment
      • Who calls the AnonCreds method to get the Revocation Registry from the ledger for verification
        • Verifier or AnonCreds?
      • 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 or the Verifier (calling AnonCreds) should calculate “within interval” (using 2.) and mark verification true if the RevRegEntry used by the Prover is within the interval, else false.
          • Dangers:
            • 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.
      • Decision – add an optional `at_from_ts` set of entries, one per NRP, that AnonCreds can use for determining if the holder_ts is within the Presentation Request interval.
    • Issue #137 added regarding further investigation into what happens to the issuance data flow nonce(s) by Belsy
      • No progress yet.
  • Discussion: Mike Lodder has proposed that a group start on "Next Gen" AnonCreds based on his this recorded presentation at out 2022-11-28 meeting
    • Interest in this – figure out way to do this.
  • 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