Transferable Constant-Size Fair E-Cash

We propose an efficient blind certification protocol with interesting properties. It falls in the Groth-Sahai framework for witness-indistinguishable proofs, thus extended to a certified signature it immediately yields non-frameable group signatures. We use blind certification to build an efficient (offline) e-cash system that guarantees user anonymity and transferability of coins without increasing their size. As required for fair e-cash, in case of fraud, anonymity can be revoked by an authority, which is also crucial to deter from double spending.

• Type: Conference
• Year: 2009
• Where: CANS
• Authors: Georg Fuchsbauer, David Pointcheval, Damien Vergnaud
• Keywords: Blind Certification, Blind Certification Protocol, CANS 2009, Cryptology, Non-frameable Group Signatures