The Research Of Trust Evaluation Model In Web Services Environment

Web service as a new mode of commercial applications, and it is inevitably result of distributed computing model of development, Safety be affected the development of the important factors. Trust evaluation model provides the way to solve Web services security problems. At present web services trust property and assessment mechanisms exist insufficient in the web service model,which cause the web service interactive failure. Therefore,research the non-functions attributes of service quality relating to web service trust,and establish an effective mechanism in the evaluation model for web service to reduce the risks of key factors.Improved trust model of web service ,which effectively evaluate the services trust relationship,improve the services interact the success rate and resove web services security problems. On the study of Web service trust evaluation model , the main concerns aspects as follows:First, we define the concept and relationship attribute of the web service trust, and the service interactive relationship.compare the number of history interactive records and system set threshold,we can infer the services node interactive relationship, According to relevant attribute of historical records to calculate the initial credibility;If it is direct trust relationship,we can use the principle of iowa operator,the time is considered as induced value which use historical trust records to sort,and calculate this interactive trust.because the characteristics of the dynamic changes of time makes the model has strong dynamic adaptability.Secondly,if the web service interactive action is indirect trust relationship,when trust information aggregated in the feedback,this model use feedback trust information to search and aggregate based on the direct trust.as evaluation of the direct trust can be update ,which ensure the authenticity of the feedback information.in addition,we design the model add the reward and punishment mechanism ,this mechanism can achieve reward of honest nodes and punishment of malicious or unrealistically high dishonest.thereby reducing the network bandwidth and improve the speed of information aggregation,and enhancing the security of the model.when calculate the overall trust ,this model use the function of history record as the weight factor of direct and indirect.this method can overcome the lack of subjective jugements of confirmation weight in the existing model.Finally, through a simulation experiment,it can be validate that the trust evaluation model is reasonable and effective in the context of Web service.To sum up,we suggest that some questions should be further depth study and explore.