Research On Trust Evaluation Model In Web Services

In recent years, with the development of computer network technology and application, Web services, as a new kind of business application pattern, is widely applied to many websites because it has the advantages of open system, flexible structure, platform-independent, easy design and low-cost. As Web services technology progresses, many Web service entities with the same or similar functions but non-functional attributes have appeared on the Internet. At present, the description of trust attributes and assessment mechanism exists insufficient in the Universal Discovery Description and Integration of web services, so we can not ensure that each Web service entity is credible, which causes that Web service interaction faces with security issues. Trust evaluation model provides a security way to solve Web service interaction. Therefore, in order to select a high-quality service from the set of Web services with the same or similar functions, the attributes of quality of service, such as availability, reliability and so on, relating to web service trust is considered, a rational and effective trust evaluation model for web services is builded. It not only can help service requestor to select a high-quality and high-trust Web services, but also can reduce the risk of Web service interaction and guarantee the interactive security of Web services. In the research of Web services trust evalution model, we have done some researches as follows:1、The fuzzy nature of subjective trust is considered, the fuzzy theory is introduced to the trust evaluation model of Web services in order to effectively resolve the model of subjective and fuzzy trust.2、The attributes of quality of service relating to Web services trust are considered, and the fuzzy theory has been used to model the issues of web service trust. The model provides a formal description of the Web Services trust, it also provides a fuzzy comprehensive evaluation method of web services trust based on information entropy. This method uses subjective and objective combination weight approach could reasonably distribute the weight of trust evaluation factors set, it shows a combination of subjectivity and objectivity and perfects the trust evaluation mechanism, which overcomes the shortage of traditional method, in which the weight is set up by subjective manners, and makes the model have a better rationality and higher practicability.3、In order to resolve the problem of trust transitivity and combination, the model provides a trust derivation mechanism which is based on the formal description of web services trust in the path of multi-recommender. According to the dynamic character of trust and the idea of trust updated at regular intervals, a new model of trust renewal is provided, which is based on the close degree in fuzzy theory, and which can update trust relationships automatically.Finally, through a Simulation experiment, it can be validated that the trust evaluation model is reasonable and effective in the open and dynamic environment of Web services.