2023-03-20 AnonCreds v2.0 Working Group Meeting

Summary

• Proposed AnonCreds v2.0 Data Models - Presentation - Mike Lodder
• Open Discussion

Recording of Call: dummyfile.txt

Segment – Awesome Presentation by Mike Lodder: dummyfile.txt

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>

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

Related Repositories:

• Mike Lodder's proposed Data Models: https://hackmd.io/ZlsnLoclSveePJOZljgMfA
• AnonCreds v2.0 Specification Repository: https://github.com/hyperledger/anoncreds-spec-v2/
• AnonCreds v1.0 Specification: https://hyperledger.github.io/anoncreds-spec/
• AnonCreds Methods Registry: https://hyperledger.github.io/anoncreds-methods-registry
• AnonCreds Rust Open Source Code: https://github.com/hyperledger/anoncreds-rs

Goals of the Working Group:

The goal of AnonCreds v2.0 is to retain and extend the privacy-preserving features of AnonCreds v1.0, while improving capabilities, performance, extensibility, and security.

Meeting Preliminaries:

• Welcome and Introductions
• Announcements:
  • IIW – April 18-20 – Let's plan some presentations.
  • New v2.0 Specification Repository created.
• Updates to the Agenda

Agenda

• Mike Lodder will continue a discussion of the Data Models he is proposing for AnonCreds v2.0, this time talking about Presentations
  • Data Models HackMD document:  https://hackmd.io/ZlsnLoclSveePJOZljgMfA
  • Notes from Meeting:
    • Contents of the Issued Credential – easily mapped into other formats, such as the W3C VC Data Model.
      • Open question on where encoding occurs – within AnonCreds (better interoperability, less data to store, more computation) or by the Issuer.
    • PresentationSchema
      • A possibly published data structure used by the Verifier to ask for data from the Holder.
      • Atomic – when requested, a Proof based on a PresentationSchema is either proven or not.
      • Can use something like DIF Presentation exchange to AND/OR a set of PresentationSchemas in to a Presentation Request – plus adding an ID and a nonce.
      • Different types of proofs were covered – from plain signatures to range-proofs.
      • Different crypto can be used.
    • From Chat:
      • Is bulletproof more efficient than schnorr proofs?
        • Different purposes – Schnorr: Prove you know the hidden value, Bullet: Proof hidden value is in range.
      • Discussion of revocation scalability – details to be covered in a future meeting.
• Plans for IIW?
• Next Meeting (two weeks):
  • Suspension vs./as well as revocation?
  • Collect some use case specific examples and continue the discussions:
    • Applying the data structures to a real use case or two
      • Take an existing AnonCreds Schema (maybe this) and Credential Definition (maybe this) and define what it would be using Mike's proposed data models.
        • Where would the data models exist, such as on ledger, in the AnonCreds specification?
    • What concrete uses other than link-secret is there for blinded data in a credential?
  • ALLOSAUR Revocation

Future Calls

To Dos:

• Plan session for IIW on AnonCreds.

Action items