Abstract: At present, the security of the identity based proxy signature schemes was almost proven in the random oracle model, but for which any implementation of the random oracle results in insecure schemes. It is more practical to design threshold proxy signature scheme in the standard model, compared with the existing ones. This paper presented an secure and efficient ID-based proxy signature scheme (IBPS) in the standard model. The scheme's correctness was exactly proven in terms of bilinear pairing technique and its security analysis and prove was given in detail in the assumption of the computational DifficHellman problem. Compared with the known identity based scheme in the standard model, the scheme enjoys less operation.

Key words: Identity based proxy signature, Standard model, Identity based cryptography, CDH-problem