基于概念格的RBAC模型中角色最小化问题的理论与算法

基于概念格的RBAC模型是角色挖掘中的一个重要方向,在概念格上找出满足最小权限原则的最小角色集合有助于降低安全管理的复杂性.本文研究了在概念格的RBAC模型上的角色最小化问题及其算法.首先将角色最小化问题引入概念格模型,并给出了概念格模型上最小角色集、角色替代和角色约简的定义,和相关定理的证明.在此基础上建立了一个基于角色替代的角色最小化问题求解模型,并设计了一个贪婪算法.该算法以对象概念集为初始集,逐个将集合中的概念用它的父概念来替代和约简,自底向上地迭代求解最小角色集.实验与分析表明了本文相关理论和算法的有效性.

Theory and Algorith m for Roles Mini mization Proble m in RBAC Based on Concept Lattice

Roles minimization problem and its algorithm based on RBAC model are studied in this paper.Roles minimization problem is introduced into concept lattice model.The minimal set of roles,roles replacement and roles reduction are defined,and the corresponding theorems are proved.Based on this,the model of solving roles minimization problem based on roles replacement is created and a greedy algorithm is proposed.In this algorithm,the object concepts set is regarded as initial set,concetps in roles set are replaced and reducted by their parents one by one,and the minimal set of roles is solved by iteration in bottom-up way.Experiments show that the theory and the proposed algorithm are effective.