An efficient identity-based proxy signature scheme in the standard model with tight reduction

Abstract

Identity-based proxy signature (IDPS) is a special signature. It has many applications, such as distribution networks, mobile communication, etc. Numerous IDPS schemes have been proposed. However, most existing IDPS schemes suffer the following shortcoming: loose security reduction. This problem is very important because loose security reduction weakens the security of IDPS and makes IDPS more vulnerable to attack. In this study, based on Kang et al.’s proof technical, we propose a new identity-based proxy signature scheme with a detailed security proof in the standard model. We also reduce the security of our scheme to the hardness assumption of computational Diffie-Hellman. In order to present the advance of our scheme,we make a theory comparison between our schemewith other identity-based proxy signature schemes in terms of security reduction and computational cost. The comparison shows that our scheme has tightest security reduction. What’s more, our scheme needs less computational cost that is almost half of other schemes.