2024-05-13 AnonCreds Working Group Meeting
Summary
Revocation Specification – https://hackmd.io/LGlyexsRSBqrm7TIKzzZ_A?view
What's happening at the W3C VC-DI-BBS Working Group - Discussion about next steps
Getting BBS Support in AnonCreds v2
Reminder: New Meeting Times
Time: 7:00 Pacific / 16:00 Central Europe
Call Link: https://zoom.us/j/97954159540?pwd=WWk3WmQ3MVh1SXBYZGVreGl0QllGdz09
Recording:
Notices:
This specification creating group operates under the Linux Foundation Community Specification License v1.0.
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Meeting Attendees
@Stephen Curran (BC Gov / Cloud Compass Computing Inc.) <swcurran@cloudcompass.ca>
Related Specifications and Repositories:
AnonCreds v1.0:
The v1.0 specification is published here: https://hyperledger.github.io/anoncreds-spec/
The Working Group uses this GitHub repository to manage the specification: https://github.com/hyperledger/anoncreds-spec
The AnonCreds Methods Registry: https://hyperledger.github.io/anoncreds-methods-registry
The v1.0 implementation in Rust is here: https://github.com/hyperledger/anoncreds-rs
The v1.0 implementation is dependent on this Rust CL Signatures implementation: https://github.com/hyperledger/anoncreds-clsignatures-rs
AnonCreds v2.0
The initial framework for the v2.0 specification repository is here: https://github.com/hyperledger/anoncreds-spec-v2
The v2.0 implementation in Rust is here: https://github.com/hyperledger/anoncreds-v2-rs
Underlying AnonCreds v2.0 are cryptographic libraries in Hyperledger Labs Agora
Meeting Preliminaries:
Welcome and Introductions
Announcements:
Workshop Wed. April 24th: Zero Knowledge Proofs and ZK Programming in Blockchain Application Development
Any updates to the Agenda?
Agenda
Specification for Privacy Preserving, Scalable Revocation – https://hackmd.io/LGlyexsRSBqrm7TIKzzZ_A?view – Mike Lodder
How is binding done to between the credential and the revocation?
How are keys managed when there are multiple revocation managers (multi-party computation configuration)?
VC-DI-BBS Specification and AnonCreds V2 – getting to collaboration?
BBS Signatures specification is moving through IETF – https://datatracker.ietf.org/doc/draft-irtf-cfrg-bbs-signatures/
Incubation happening at DIF
DHS has announced support for using BBS Signatures for selective disclosure and unlinkability
Intended approach is to use Parallel Signatures, and to sign VCs with a NIST approved signature and BBS Signatures
W3C Working Group has a release candidate spec – vc-di-bbs
Selective disclosure, unlinkability, holder binding, pseudonyms (issuer and holder defined) (directed identifiers)
Left off – revocation (!!), blinded secret, claim equality, set membership, range proof, signed integer
RDF Canonicalization is used – JSON-LD-based, and same as other VC-DI cryprosuites
Getting BBS Support into AnonCreds v2
Reminder of new meeting times
Second Monday of each month – 7:00 Pacific / 16:00 Central Europe
Fourth Monday of each month – 15:00 Pacific / 16:00 Mountain / Super Late Central Europe (Midnight...) / 10:00 Auckland
Open Discussion
Using an accumulator as a space-efficient way to enable set membership of hashes? For example:
Up to a million high-entropy hashes
Only needed query: "is hash XYZ in the set (Y/N)?" – e.g., given hash XYZ and the accumulator, can I answer that question?
To Dos:
Action items
Links to be referenced in the spec and used where needed: