一个优化的公平的电子支付方案

在电子商务中，交易双方往往是互不信任的，交易中的任意一方总担心另一方在交易过程中处于比自己更加有利的位置，从而可能使自己蒙受损失，公平的电子支付方案和协议就是为解决这类问题而设计的，该文借鉴转化数字签名的思想，提出了一个公平的电子支付方案，使交易中的双方在方案中处于平等的位置，实现了交易过程的公平性，该方案涉及到一个可信任的第三方（TTP），但只有在注册阶段和产生争议的时候，才会涉及到TTP，正常的支付过程并不需要TTP，也就是说TTP的引入并不影响支付过程的效率，因而该方案是一个“优化“意义上的公平的电子支付方案。

An Optimistic Fair Electronic Payment Scheme

Making use of the idea of convertible digital signature, this paper proposes a new fair electronic payment scheme based on a new interactive verification protocol that is proposed in the paper too. The security of the scheme is based on the hard question of discrete logarithm. The scheme makes both sides in equal positions during the course of electronic transaction. And then, the fairness of electronic transaction is achieved. A trusted third party (TTP) is involved in the scheme to guarantee the fairness of the scheme for both sides. However, only during the course of registration and dispute resolution will TTP be needed. TTP is not needed during the normal payment stage. That is to say, it does not affect efficiency of payment to involving TTP. So the scheme is a fair electronic payment scheme in "optimistic" sense.