Message recovery fair blind signature

Abstract

As the blind signature introduced by Chaum [10] does not reveal any information about the message or its signature, it has been used for providing the anonymity in secure electronic payment systems. Unfortunately, this perfect anonymity could be misused by criminals as blind signatures prevent linking the withdrawal of money and the payment made by the same customer. Therefore, we should provide publicly verifiable mechanism if it is required for the judge to trace the blackmailed messages. In this study, we propose a modified fair blind signature, which additionally provides the role of message recovery. After analyzing the existing meta-ElGam,al scheme [12] suggested by Horster, the model of message recovery blind signature is considered at first. And we suggest a new fair blind signature based on the oblivious transfer protocol, with which a judge can verify its fairness. Proposed scheme can be advanced into the blind multi-signature and it is also applicable to the diverse payment applications.