Research On Web Services Trust Model Based On Bayesian Networks

Web services is a new kind of distributed computing technology. All standards of Web services are based on XML. Therefore, it inherits good data interoperability and expansibility of XML, and also it is loose coupling and cross-platform. Web services expands Web capacity and makes Web to be a distributed computing platform developing from traditional platforms, which provide information and function simply orienting human. At the same time, because of the existence of these features, Web services system is facing many security threats not only from the outside of system, but also from the internal. As we know, to ensure the security of the system, traditional distributed computing technologies mainly rely on the password techniques resisting system from external malicious behaviours. However, traditional methods can not solve internal system threats. So, it is necessary to evaluate the behaviors of services entities druing the communication activities, and to understand the credibility provided by the entities.Therefore, the concepts of trust and trust model are introduced. By studying the trust mechanism, safety problems caused by open, uncertainty and dynamic characteristics and etc of Web services network are solved. So far, there's no unified and recognized definition about trust. Trust is a kind of credibility reflecting credibility, reliability and ability to complete a certain function and etc of entities in the trust relationships. At present, the research on trust problems has become a hot in researching and analyzing Web services security.On the basis of researching Web services and its key technologies, trust and trust model, a new Web services trust model based on Bayesian networks is established in our subject aiming at the characteristics of Web services system structure. Dynamic trust relationships among service entities in web services network are dealed with and trust is evaluated in this model. And more, corresponding methods are used to calculate direct and indirect trust value. Also, update formula on trust value is given. Simulation experiments and the results show that malicious behaviors of malicious entities are effectively punished by the trust model proposed in our subject. Accuracy and efficiency of services scheduling in Web services network are improved. And that services entities will have stronger initiative and higher accuracy on choosing services providers. Thus, security of Web services system operation can be guaranteed to a certain extent.