Web Service Trust Evaluation Model Based On Game Theory

As a new internet application model, Web services obtain great attention by the users because ofits’ feature of platform-independent, highly-integrated, intact characteristics,intactly-encapsulation,loosely coupled and so on. Web services provide features outwardly in the form of collaboration andservice,however,with the Web services’ scale is more and more bigger, there forms a huge standardcomponents in the Web services in the Internet, in which there are a lot of the same or similar functionservice,there even existence of some malicious and false service.Therefor, how to select a satisfied andcorrect Web service for users is a urgent problem. This paper will present a Web service trust evaluationmodel based on game theory，aimed at resolving the collusion problems in Web services environment.First of all, to summarize the characteristics of Web services technology and the present situationof the services’ users, analyse existing web services trust evaluation’s basic idea, method andcharacteristics, Summed up the advantages and disadvantages of the existing model.Secondly, according to the trust problem, existing SOA (Service Oriented Architecture) models,the traditional SOA model is extended,the new service trust management module is added, this paperproposes a trust evaluation model whice is based game theory. The design of a mechanism to meet thegame scene is made by using the game theory and its basic elements.Thirdly, analysis all the participants’ profit by the game theory, prove the existence and optimalityof the Nash equilibrium. according to Web services’ collusion, establish a collusion detectionmechanism, Because the participants in the process of the game is to pursue the maximization of theirown interests, Prove the existence of the subgame perfect Nash equilibrium in the infinitely repeatedgame through analysely the players profits in the different strategy combination,to seek the optimalstate of the system.Finally, to establish a Web service trust evaluation system by using the proposed model,the systemcan deal with the information provided by the users according to the difference of the user domaincorrelation degree, The model is proved to be availability and availability in the aspect of collusionagainst the Web service.