Certificateless threshold signature secure in the standard model

Abstract

Threshold signature is an extension of the standard signature, in which several signers may be required to cooperatively sign messages for sharing the responsibility and authority. Certificateless cryptography eliminates the need of certificates in the Public Key Infrastructure and solves the inherent key-escrow problem in the Identity-based (ID-based) cryptography. In this paper, we propose a certificateless threshold signature scheme with concrete implementation which is provably secure in the standard model. Furthermore, this scheme is proven secure against the malicious-but-passive KGC attack. To the best of author’s knowledge, this is the first construction of certificateless threshold signature scheme that does not rely on random oracle or ideal ciphers.