混合策略下的理性交换协议模型

Rational exchange protocol model based on mixed strategy

在小额支付的交换协议中,通过TTP保证协议公平性所需代价往往高于协议本身价值,在这种情况下,理性交换协议是一种合适的选择。应用扩展式博弈混合策略理论对交换协议进行了建模,引入熵函数对交换过程中的公平性进行了描述;在保证过程公平性原则的前提下,运用混合策略纳什均衡概念形式化定义了理性公平性,并在此模型基础上构造了一个新的理性交换协议;对协议的可追究性、理性公平性进行了证明,结果表明该协议能达到混合策略纳什均衡。该协议无须可信第三方,实现了理性公平性并对惩罚值进行了优化,具有更好的适应性。

In the exchange of micropayment protocol, the cost of ensuring fairness by TTP is higher than the value of protocol, in this case the rational exchange protocol is a appropriate choice. Exchange protocol was modeled by extensive mixed strategy game and the entropy function was introduced to discuss the fairness in the process of exchange. In addition, the rational fairness was formally defined by using the concept of mixed strategy Nash equilibrium under the principle of the fairness in the process, and on the basis of this model to construct a new rational exchange protolcol. The protocol＇s accountability and rational fairness were proved, the results show that the proposed protocol can achieve mixed stratrgy Nash equilibrium. Without the participation of the trusted third party, the protocol can achieve rational fairness and optimize the penalty values, it is beautifully adapted to the real environment.