The Research Of Time-Constraint Character In Role-Based Access Control

Access control is generally concerned with determining what users and groups of users can perform what operations on what resources. With access control service, we can restrict the approach to critical resource, avoiding damage brought by illegal user's intrusions or legal user's inappropriate operations.Traditional access control techinique can be classified in two primary genres, that is,Discretionary Access Control (DAC) and Mandatory Access Control (MAC). Both of them have their own typical shortage.In 90's, Role-Based Access Control (RBAC) techinque emerges. It effectively overcomes the shortages of traditional access control techinque metioned above. It can reduce complexity of grant management and decrease the cost of management, as well as make the process of designating and executing specific policy of protection more flexible, which gives the administrator a better environment to implement policy of security.The research work of RBAC is greatly emphasized in recent years. But the main work focus on some other characters which has nothing to do with the time character.The problems of choosing the turn time point and security status recovery were mainly explained, and the algorithms of choosing the turn time point which can judge the system security status in TRBAC and choosing the reasonable teminating session set which will restore the system were proposed. Therefore , the algorithm solve the conflict, to some extent, between efficiency and security caused by which choosing the turn time point is too big or too small.