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Recording of Call: https://youtu.be/qAkODMA3dgc
Notices:
This specification creating group operates under the Linux Foundation Community Specification License v1.0.
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- Update on AnonCreds Happenings
- Discussion: Flexibility Modularity in the Underlying Signature Schemes - Mike Lodder
- AnonCreds v2.0 could use one of four (CL, BLS, BBS, and PS) signatures schemes at the moment. How does that work?
- As with CL Signatures, data is encoded as numbers
- The additional Schema Claim data allows for "improved" encoding – e.g. zero centring integer data
- The signature type and the Schema Claim data determine exactly what is needed per claim to enable comparable presentation ZKP capabilities.
- These will have to be defined in the specification – e.g.
- the requirements of the cryptography for the features, and,
- for specific signatures to be supported (perhaps BBS+ and PS), the details of using those signatures
- These will have to be defined in the specification – e.g.
- Purposes/use cases for the Schema Types proposed for AnonCreds v2.0, with a goal of leading to some useful names for the different types:
- Enumeration
- Hashed
- Numeric
- Scalar
- String
- Unsigned Byte/Binary
- Hashed: claim data is hashed before signing
- Numeric: claim data is zero centered before signing
- Scalar: claim data is already a cryptographic value. Equivalent to a null hash
- Enumeration
- Predicates:
- Hide signature – proof of signature (unlinkable)
- Hide attribute - reveal or hide - Schnorr Proof
- Set memberships, such as
- Zip/postal Code
- State
- City
- Accumulator
- Commitment - same value
- Range Proof
- Verifiable Encryption
- Commitment
- Not discussed: Claim equality across credentials (e.g. proof that the claims in two credentials are the same without sharing the value).
Future Calls
- Collect some use case specific examples and continue the discussions:
- Applying the data structures to a real use case or two
- What concrete uses other than link-secret is there for blinded data in a credential?
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