Security of NIDV Proof Systems for Certificate-Free Undeniable Signature Schemes

Undeniable signature schemes are not publicly verifiable. Therefore, in order to prove the validity/invalidity of a message-signature pair, the signer needs to provide a proof for the rightful verifier. Since the introduction of undeniable signature schemes, various proof systems with different properties and features have been introduced to be incorporated in the structure of such schemes. Among all, the noninteractive designated verifier proof generation system of Jakobsson et al. with its distinguishing properties and features has been recognized as the most practical proof system. Due to its interesting features, a variation of Jakobsson et al. proof system has been employed in all of the proposed identity-based and certificateless undeniable signature schemes. In this paper, we analyze the security of the variation of such proof system in identity-based settings and present a secure identity-based non-interactive proof system with complete set of security proofs.