Abstract: Traditional methods arc hard to describe the subsume relationship of subjects and objects among some access control rules. In this paper, we built an algorithm based on logic unify to resolve which problem. Firstly, we converted access control request to logic question, obtained the access control result by means of logic answer. Next, we utilized the facts to describe the each component of access control, and we realized the flexible access control by using the dy- namic instantiation of variables in non-ground facts during the system running period. Finally, our experiment results show that our algorithm is effective.

Key words: Access control,Logic unify,Rule description