A note on anonymous credentials using BLS signatures
This provides an incremental improvement for building anonymous credential systems in client-server or distributed ledger applications.
The authors demonstrated that BLS signatures' aggregation property enables efficient Content Extraction Signatures for building digital credentials supporting selective disclosure, and sketched a protocol combining this with NIZK proofs for predicate satisfaction while keeping data secret.
In this note, we remark that the aggregation property of the BLS signature scheme yields an efficient Content Extraction Signature (CES). This construction can be used to build digital credentials that support selective disclosure in various settings. Interestingly, this construction is efficient and well suited to build credential issuance schemes with various applications in the client-server or in the distributed ledger models. Finally, we sketch a protocol that combines the CES with the use of a NIZK which allows to prove predicate satisfaction on claims extracted from a credential, while keeping the data secret.