Efficient Identity Based Signature Schemes Based on Pairings

We develop an eecient identity based signature scheme based on pairings whose security relies on the hardness of the Diie-Hellman problem in the random oracle model. We describe how this scheme is obtained 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 signature schemes. We further discuss issues of key escrow and the distribution of keys to multiple trust authorities. The appendix contains a brief description of the relevant properties of supersingular elliptic curves and the Weil and Tate pairings.