Mix-networks on permutation networks

Abstract

Two universally verifiable mix-net schemes that eliminate the cumbersome Cut-and-Choose method are presented. The construction is based on a permutation network composed of a network of 'switches' that transposes two inputs. For N inputs and t tolerable corrupt mix-servers, the schemes achieve O(tN logN) efficiency in computation and communication while previous schemes require O(?mN) for error probability 2 -k and m mix-servers. The schemes suit small to middle-scale secret-ballot electronic elections. Moreover, one of the schemes enjoys less round complexity so that servers do not need to talk to other servers except their neighbors unless disruption occurs.