Abstract:

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.

Key words: rational exchange protocol, mixed strategy, process fairness, Nash equilibrium