Efficient identity-based signature scheme in the standard model

Constructing identity-based signature(IBS) secure in the standard model is one of the active topics of current cryptography. We present a new efficient IBS scheme without random oracles and prove that it achieves adaptive identity, chosen plaintext security. Our scheme is obtained from a modification of Gentry´s recently proposed identity based encryption scheme. It is constructed based on the truncated decisional augmented bilinear Diffie-Hellman exponent assumption (ABDHE) and it is an efficient signature scheme, which achieves O(1)-size public keys, O(1)-size signatures. Besides, either public keys and signatures has no relation with the number of participants, and the number of pairing computations needed for signing and verifying is only one time. Compared with other IBS systems, our scheme has comparable properties and computation efficiency.