Untraceability of Partial Blind and Blind Signature Schemes

摘要

Blind Signature is employed in privacy related protocols, where signer signs on a blinded message. It provides anonymity in various cryptographic applications such as electronic voting, digital cash system etc. Concerning the need for quantum resistant scheme, Ruckert and Tian et al. proposed the lattice based blind signature and partial blind signature schemes respectively. But, both the schemes left out one of the security requirement of a blind i.e. Untraceability, where the signer can't link the blinded signature with a valid message-signature pair even when it is revealed in public. In this article, we propose an attack on the untracebility property of both the schemes. The proposed attack opens the door for researchers to work on quantum resistant untraceable blind signature.