With rapid development of computer network technologies, video applications based on network has been more and more common. Video payment services has been more and more important, the grows of applications in this area lead to an effect that research on how to carry fair online exchange protocols on internet has been more and more attractive. So, fair exchange has been a key point, that is, how to exchange services in a fairness way on internet, among these, how to make insurance of the fairness of the exchange business is the key of the use. Fairness means during any parts of the protocol performing, any of the involved parties takes no advantages of another. Fairness has two meanings:first, when protocol ends, it should satisfy the accountability, and ensure that two parties get their non-repudiation evidences, namely ensure that the sender gets the EOR(evidence of receipt) and the receiver gets the EOO(evidence of origin), then, if the protocol ended abnormally, the protocol should ensure that two involved parties in the communication at a equally status, neither of them takes advantages of another. The fair exchange business is the security electronic exchange business that satisfied the fairness.This paper first introduces the fairness knowledge of some security electronic exchange business, and select a new unique formalization logic analyzing method proposed by Qin Sihan, and propose some solution for the unfair phenomenon existed in the protocol, and base these, we analyze the shortcomings and limitations of the three protocols mentioned above, and we improve them, then based these problems and their solutions, this paper proposed two new fair exchange business protocol and analyzes it with the new unique formalization logic analyzing method. The new protocol not only satisfies the fairness, but also performs fineness in security. At the end of the article, we also discuss the shortcomings and limitations of the new protocol. |