Efficient Identity based Signature Schemes based on Pairings.

We develop an e cient identity based signature scheme based on pairings whose security relies on the hardness of the Di e-Hellman problem in the random oracle model.We describe how this scheme is ob- tained as a special version of a more general generic scheme which yields further new provably secure identity based signature schemes if pairings are used.The generic scheme also includes traditional public key signa- ture schemes.We further discuss issues of key escrow and the distribution of keys to multiple trust authorities.The appendix contains a brief de- scription of the relevant properties of supersingular elliptic curves and the Weil and Tate pairings.