Fair electronic exchange using biometrics

摘要

Fair exchange between two parties can be defined as where: either both parties acquire what they expected or neither does. Protocols that facilitate such transactions are known as "fair exchange protocols". We analyze one such protocol for contract signing that was presented by Micali. In this paper we show that Micali's protocol is not completely fair and demonstrate the possibilities for one party to cheat by obtaining the other party's commitment and not offer his. A revised version of this protocol by Bao et al. provides improved fairness by handling the above mentioned attack but does not handle replay attacks. Our proposed protocol improves upon the revised protocol by addressing replay attacks and removing redundant information from signatures thus making the overall transmission smaller. Our protocol also provides client authentication using a finger print based authentication technique and our use of hybrid encryption using Elliptic Curves instead of first generation techniques furtherimproves efficiency.