Design and research of an improved RBAC model

Analyze the defect of Role Based Access Control and Task Based Access Control model. Based on the two models, put forward an improved Role Based Access Control model to meet the demand of distributed network environment. The formalized definition and constraint are also presented. The new model imports the concept of virtual organization and service flows. Solve the conflict of the model by a new method. The method combines three policies with each other. The policies are administrator priority, refusing grant priority and authorization priority. Through the analysis, the model can meet the demand of distributed environment and can be realized easily.