Provably Secure Certificateless Proxy Signature Scheme in the Standard Model

Provably Secure Certificateless Proxy Signature Scheme in the Standard Model

Proxy signature frees the original signer from the heavy signature work. Many certificateless proxy signature (CLPS) schemes have been proposed in the last ten years. The security proofs of most known schemes are given in the random oracle model (ROM). There are only two CLPS schemes with provably security in the standard model (SM). However, in which the size of the system parameter increase linearly with the size of the user’s identity information. That increase the storage burden of the key generation center. In this paper, a new CLPS scheme is constructed and the security proofs are showed in SM. The size of system parameters and the master key are constant in the scheme. Requiring only three pairing operations, the new scheme is more efficient and suitable for mobile computing.