2023-09-25 AnonCreds v2.0 Working Group Meeting

Summary

• Hyperledger Labs Agora – an implementation of (the planned) AnonCreds 2.0 – and more!
• Open Discussion

Zoom Link: 

Recording of Call:  

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>

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:

Agenda

• Hyperledger Labs Agora – an implementation of (the planned) AnonCreds 2.0 – and more!
  • We're excited to have Mike Lodder on our AnonCreds call this Monday, September 25 (7:00 Pacific / 16:00 Central Europe) to discuss the newly accepted Hyperledger Labs project "Agora", a set of repositories that implement the AnonCreds v2.0 specification that we have been discussing, and more. Mike has been working on this implementation for the past several years and we're excited to have the code available to use and expand upon. The implementation enables the new features that have been envisioned for AnonCreds v2.0, an evolution of the existing AnonCreds specification/implementation:
    
    
    • Flexibility in the underlying signatures, including support for BBS+, PS and CL Signatures.
    • Expanded Issuer/Holder access to ZKPO capabilities, such as set membership, range proofs, verifiable encryption and more
    • The familiar participants, interactions, and objects from AnonCreds, enabling a clear path to adoption

Plus a number of other generally useful cryptographic libraries that will be helpful for developers. An example is a key ring library for protecting secrets in memory from side channel attacks like Row hammer and ram bleed. Lots of fun/powerful tools for this space!

• Open Discussion

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?

To Dos:

Schema Claim Type:

• Would it make sense defining encodings for date related schema claim types that are especially useful to use in ZKP predicates?
  • "iso860_date" – encodes to dateint e.g., 2023.06.26 is 20230626
  • "iso860_datetime" - encodes to Unix Time e.g., seconds since Jan 1, 1970
• Yes – these would be "numbers" by type, but with special encoding handling.

Action items