Provably secure proxy signature scheme from factorization

Proxy signature is a cryptographic primitive used for delegating the signing rights. The security of most existing proxy signature schemes is based on the complexity assumptions of discrete logarithms and the intractable problems of elliptic curves. While several proxy signature schemes from integer factorization were proposed, unfortunately they cannot resist against the attacks lunched by a malicious original signer or a malicious proxy signer. Hence, it is an interesting research problem on how to construct a provably secure proxy signature scheme based on factorization. In this paper, we propose a new construction of proxy signature whose security is reduced to the integer factorization problem in the random oracle model. We demonstrate that our scheme outperforms the other existing schemes in terms of security, computational efficiency and the length of the public key. Our scheme is the first provably secure proxy signature scheme from integer factorization.