Malleable Proof Systems and Applications

sion of an extended abstract published in Proceedings of Eurocrypt 2012, Springer-Verlag, 2012. Available from the IACR Cryptology ePrint Archive as Report 2012/012. Malleability for cryptography is not necessarily an opportunity for attack, but in many cases a potentially useful feature that can be exploited. In this work, we examine notions of malleability for non-interactive zero-knowledge (NIZK) proofs. We start by defining a malleable proof system, and then consider ways to meaningfully control the malleability of the proof system, as in many settings we would like to guarantee that only certain types of transformations can be performed. We also define notions for the cases in which we do not necessarily want a user to know that a proof has been obtained by applying a particular transformation; these are analogous to function/circuit privacy for encryption. As our motivating application, we consider a shorter proof for verifiable shuffles. Our controlled-malleable proofs allow...

• Type: Journal
• Year: 2012
• Where: EUROCRYPT
• Authors: Melissa Chase, Markulf Kohlweiss, Anna Lysyanskaya, Sarah Meiklejohn
• Keywords: Cryptology, EUROCRYPT 2012, Malleability, Proof System, Proof Systems