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2023-01-30 AnonCreds Specification Working Group Meeting

2023-01-30 AnonCreds Specification Working Group Meeting

Jan 30, 2023

Summary

  • Revocation Interval

  • Getting started on AnonCreds v2 Discussion?

  • Progress on the anoncreds_rs implementation

  • Open Discussion

Recording of Call:

Notices: 

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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