Universal Designated-Verifier Partially Blind Signatures for E-Commerce

Abstract

Blind signature schemes can prevent the information of a signature and message pair from leaking to the signer. Partially blind signature is a signature of which the message containing some information agreed by the signer and the signature requester is in an unblinded form. To protect the privacy of partially blind signature holders from leaking out by verifiers, we introduced universal designated-verifier partially blind signatures, in which any holder of a partially blind signature can convert the partially blind signature into a designated-verifier signature. Given the designated-verifier signature, only the designated verifier can verify that the message is signed by the signer, but he is unable to convince anyone else of this fact. In this paper, we also proposed a universal designated-verifier partially blind signature scheme from bilinear pairings based on Chow et al.’s public key infrastructure (PKI)-based partially blind signature scheme. Finally, we illustrate the application of the universal designated-verifier partially blind signatures that they can be used in untraceable electronic commerce systems and other trust negotiation systems.