Provably Secure Blind Threshold Signatures Based on Discrete Logarithm

Abstract

In this paper, we propose a provably secure group-oriented blind (t,n) threshold signature scheme which is the first scheme, such that, its security is proved as equivalent as the discrete logarithm problem in the random oracle model. By the scheme, any t out of n signers in a group can represent the group to sign blind threshold signatures, which can be used in anonymous digital e-cash systems or secure voting systems. By our proposed scheme, the issue of e-coins is controlled by several authorities. In our scheme, the size of a blind threshold signature is the same as that of an individual blind signature and the signature verification process is equivalent to that of an individual signature.