Efficient and provably-secure certificateless short signature scheme from bilinear pairings

In this paper, we present a certificateless signature (CLS) scheme that is proved to be secure in the random oracle model under the hardness assumptions of k-CAA and Inv-CDHP. Our scheme upholds all desirable properties of previous CLS schemes, and requires general cryptographic hash functions instead of the MapToPoint hash function which is inefficient and probabilistic. Furthermore, our scheme requires less computation cost and significantly more efficient than all known CLS schemes, and the size of signatures generated by our scheme is approximate 160 bits, which is the shortest certificateless signatures so far. So it can be used widely, especially in low-bandwidth communication environments.