Secure and Efficient Identity-Based Proxy Signature Scheme in the Standard Model Based on Computational Diffie–Hellman Problem

Abstract

Identity-based proxy signature (IDBPSE) has attracted many researchers and scholars since it can simplify key management procedure of certificate-based public key setting. Recently, some IDBPSE schemes are constructed in the standard model. However, most of them have very loose security reductions. And they cannot resist the attack from the delegator and have low computational efficiency. In this study, a novel and efficient IDBPSE scheme is constructed, and we also prove its security based on the computational Diffie–Hellman assumption. Compared with other existing IDBPSE schemes, our scheme has two main advantages: tight security reduction and more complete security including resisting the delegator attack. And our scheme has more efficient performance including less computational cost and shorter signature size than most of existing similar IDBPSE schemes. What is more, our scheme does not require secure channels to transfer delegation keys, but other identity-based proxy signature schemes need.