Efficient and verifiable shuffling and shuffle-decryption

Abstract

In this paper, we propose an efficient protocol for proving the correctness of shuffling and an efficient protocol for simultaneously proving the correctness of both shuffling and decryption. The former protocol is the most efficient in computational and communication complexity among 3-move honest verifier perfect zero-knowledge protocols for proving a shuffling of ElGamal cipher-texts. The latter protocol is the most efficient in computational, communication, and round complexity, as a whole, in proving the correctness of both shuffling and decryption of ElGamal cipher-texts. The proposed protocols will be a building block of an efficient, universally verifiable mix-net, whose application to voting systems is prominent. copyright © 2005 the institute of electronics, information and communication engineers.