An efficient anonymous proxy signature scheme with provable security

Since the concept of proxy signature was introduced in 1996, many proxy signature schemes have been proposed. Among of them, the requirement of proxy signer's privacy protection is needful in some practical applications. In this paper, a new and provably secure anonymous proxy signature scheme from bilinear pairing, which is the organic combination of proxy signature and ring signature, is proposed to provide the privacy protection for the proxy signer. As for the security analysis, we classify the adversaries into three types according to different resources they can obtain and prove in the random oracle model that, the proposed scheme is unforgeable against all kinds of adversaries. Compared with Zhang et al.'s proxy ring signature scheme proposed in 2003, our scheme is more efficient in computation.