Due to the fact that foreign companies defeated Chinese companies in water industry with the strategy of "High Price, Unfair Competition" , this paper analyses the management of Limited Real Right, and presents its benefits to Chinese Water market.

By using the concepts of role-permission inheritance limit and extreme limit in the relation of role-permission assignment,the role permissions are divided into private permissions and public ones,and the concepts of privatizing inheritance and publicizing inheritance are defined.

In order to overcome shortages of the processing method of RBAC96 model′s private permission,an improved model is put forward from a point of implementation view.

The model solves privileges-inherit and private privileges by the privileges-extend-depth and realizes dynamical responsibility-divided by the role proxy mechanism and proposes the methods of implementing static responsibility-divided and operational responsibility-divided.

An access control scheme for synchro-coroutine,an algorithm to calculating public authorities and an automatic coding method are proposed to resolve the problems resulted from information sharing using synchro-coroutine among cooperant members,including illegitimate access,efficiency problem and the problem of how to control dynamic created information.

Research on Private Privilege

A problem of private privileges that child role couldn t obtain because of inherited relation in the RBAC model of information grid was researched,two present resolvations that used private roles and deepness fist notes were analyzed,from which they could result in role inflate and compages explosion.