A New Undeniable Signature Scheme Using Smart Cards

This paper proposes a new undeniable signature scheme which is based on Chaum-van Antwerpen undeniable signature scheme. In this paper, we extend Chaum-van Antwerpen undeniable signature scheme to take into account smart cards, which are famous for their tamper-resistant feature. And, we also add additional process of authenticating signer to verification and disavowal protocol of Chaum-van Antwerpen undeniable signature scheme. By these modifications, attempts to repudiate or deny a valid signature can be prevented or detected with higher efficiency. With authentication and smart cards, our scheme can be used for settling up disputes over forgeries of signatures, signature repudiations or fraudulent claimants.