A provable secure anonymous proxy signature scheme without random oracles

In order to protect the proxy signers’ privacy, many anonymous proxy signature schemes which are also called proxy ring signatures, have been proposed. Although the provable security in the random oracle model has received a lot of criticism, there is no provable secure anonymous proxy signature scheme without random oracles. In this paper, we propose the first provable secure anonymous proxy signature scheme without random oracles which is the combination of proxy signature and ring signature. For the security analysis, we categorize the adversaries into three types according to different resources they can get and prove in the standard model that, our proposal is anonymous against full key exposure and existential unforgeable against all kinds of adversaries with the computational Diffie–Hellman and the subgroup hiding assumptions in bilinear groups.