Differential Trust: Dynamic Multi-Authority Anonymous Credentials with Epoch-Weighted Updates
Researchers propose MA-ACEW, the first multi-authority anonymous credential model with epoch-weighted issuance and efficient cross-epoch credential updates.
The paper introduces MA-ACEW, a multi-authority anonymous credential scheme that weights authorities differently during credential issuance, targeting decentralized systems such as Proof-of-Stake networks. Its core primitive, Epoch-Bound Pointcheval-Sanders Signatures (EB-PS), binds signatures to time epochs, enabling non-interactive credential updates when authority weight distributions change. The authors formalize EUF-eCMA unforgeability and prove unforgeability, anonymity, and blindness under a novel STB-GPS assumption. Aggregating a credential from 128 partial credentials takes about 10.68 ms on average.