A robust coalition-resistant threshold signature scheme with anonymous signers

Abstract

In this paper we present a novel robust coalition-resistant (t, n) threshold signature scheme with anonymous signers. Only t or more group members can generate signatures on behalf of a group with n members, while any t-1 or fewer members cannot do the same thing. We construct the scheme based on a modified RSA digital signature scheme and Shamir's secret sharing scheme. The signature process consists of four phases: system setup, individual signature generation and verification, sign and verify. The designated signature combiner can verify the partial signature from the auxiliary value of the partial signature, and the scheme can resist the coalition attack from more than t malicious group members due to the use of shadow partial signature. Compared with the existing threshold signature schemes, the scheme is robust and secure, and convenient to implement. © Springer-Verlag Berlin Heidelberg 2005.