2023-04-03 AnonCreds v2.0 Working Group Meeting

Summary

Revocation Scheme Proposal ALLOSAUR - Presentation - Mike Lodder
Request: Support for Arrays and Nested data in AnonCreds
Open Discussion

Recording of Call: dummyfile.txt

Mike Lodder Presentation on ALLOSAUR Revocation: dummyfile.txt

Mike Lodder Q&A on ALLOSAUR Revocation: dummyfile.txt

Notices:

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	Hyperledger is committed to creating a safe and welcoming community for all. For more information please visit the Hyperledger Code of Conduct.

Meeting Attendees

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

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.
- Next AnonCreds V2.0 Meeting will be cancelled because of IIW
- AnonCreds Workshop presented by Hyperledger is planned for May 31, 2023, 8:00 Pacific / 17:00 Central Europe. Details to be shared.
- I'll be talking at the Linux Foundation Open Source Summit, Metaverse Conference about Hyperledger AnonCreds and ZKPs.
Updates to the Agenda?

Agenda

@Mike Lodder will continue the discussion of his proposal for AnonCreds v2.0, this time talking about the proposed ALLOSAUR accumulator/ZKP revocation scheme.
Request: Support for Arrays and Nested data in AnonCreds – @Kyle Robinson - Presentation: BC Digital Trust AnonCreds April 3 2023.pptx
- Supported needed for arrays and nested data.
- Suggestion is to use Data URLs (e.g., "data: application/json,...") – Aries RFC being posted Real Soon Now:
  - Holder, verifier would at least know that the Attribute contained a string that was (in this case) JSON data, and could process it accordingly.
  - However – would lose ability to selectively disclose (all or nothing) or use predicates on such data.
  - Same approach is going to be used for images in attributes – "data: image/png,...")
Plans for IIW?
Next Meeting (two weeks):
- Cancelled for IIW

Future Calls

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?