On the Impossibility of Three-Move Blind Signature Schemes

We investigate the possibility to prove security of the well-known blind signature schemes by Chaum, and by Pointcheval and Stern in the standard model, i.e., without random oracles. We subsume these schemes under a more general class of blind signature schemes and show that finding security proofs for these schemes via black-box reductions in the standard model is hard. Technically, our result deploys meta-reduction techniques showing that black-box reductions for such schemes could be turned into efficient solvers for hard non-interactive cryptographic problems like RSA or discrete-log. Our technique yields significantly stronger impossibility results than previous meta-reductions in other settings by playing off the two security requirements of the blind signatures (unforgeability and blindness).

• Type: Conference
• Year: 2010
• Where: EUROCRYPT
• Authors: Marc Fischlin, Dominique Schröder
• Keywords: Black-box Reductions, Blind Signature Schemes, Cryptology, EUROCRYPT 2010, Standard Model