An efficient RSA-based certificateless signature scheme

Until now, the only known construction of certificateless signature scheme is mainly based on the rather new and untested assumptions related to bilinear maps. But the implementations of pairings are more time-consuming than exponentiation operator in a RSA group. As an industry standard cryptographic algorithm, RSA is widely applied in real-life scenarios and provides many interfaces for the applied software. However, to the best of our knowledge, there does not exist RSA-based certificateless signature scheme. To overcome this problem, we present a RSA-based construction of certificateless signature scheme in the paper. And the scheme is shown to be secure in the random oracles model. The security of the scheme is closely related to the RSA problem and the discrete logarithm problem.