A verifiable secret shuffle of homomorphic encryptions

Abstract

We show how to prove in honest verifier zero-knowledge the correctness of a shuffle of homomorphic encryptions (or homomorphic commitments.) A shuffle consists in a rearrangement of the input cipher-texts and a reencryption of them so that the permutation is not revealed. Our scheme is more efficient than previous schemes both in terms of communication complexity and computational complexity. Indeed, in the case of shuffling ElGamal encryptions, the proof of correctness is smaller than the encryptions themselves. © Springer-Verlag Berlin Heidelberg 2003.