An Identity Based Proxy Re-Signature Scheme

Abstract—A proxy re-signature scheme is one which allows a semi-trusted proxy to transform a signer A’s signature on a message m, into a signature of signer B on the same message. The proxy is however not allowed to sign arbitrary messages on behalf of either signer. Several proxy re-signature schemes have been proposed, including one ID-based scheme, by Hu et al. In this paper, we describe the flaw in this scheme, with respect to the definitions of delegator and delegate security defined by Ateniese et al. We define a novel and secure ID Based proxy re-signature scheme, which satisfies these security definitions. In addition, we explore the applications of such a signature in inter-domain security. . A modified version of this signature, which can be used to transform signatures between signers in different ID-Based domains, is detailed.