Paper 2005/386

A New Short Signature Scheme Without Random Oracles from Bilinear Pairings

Fangguo Zhang, Xiaofeng Chen, Willy Susilo and Yi Mu

Abstract

In this paper, we propose a new signature scheme that is existentially unforgeable under a chosen message attack without random oracle. The security of our scheme depends on a new complexity assumption called the $k$+1 square roots assumption. We also discuss the relationship between the $k$+1 square roots assumption and some related problems and provide some conjectures. Moreover, the $k$+1 square roots assumption can be used to construct shorter signatures under the random oracle model. As some applications, a new chameleon hash signature scheme and a on-line/off-line signature scheme and a new efficient anonymous credential scheme based on the proposed signature scheme are presented.

Note: We reorganized the paper and added an anonymous credential scheme as another application of the proposed signature scheme.