eprint.iacr.orgpaper

Censorship Resistance in Credential Systems and Application to the EUDI Wallet

ePrint paper that defines a security model for censorship resistance in anonymous credential systems, where a malicious issuer uses information gathered at issuance to selectively deny credentials. It gives a round-optimal construction built on blind signatures with selective disclosure at presentation. It also presents CRACS, an instantiation for the European Digital Identity Wallet (EUDIW). CRACS keeps selective disclosure and adds unlinkability between issuance and presentation. It confines the advanced cryptography to issuance, so secure elements, credential formats, signature schemes and verifiers stay unchanged and deployment can be incremental.