中文摘要：

论文在研究现有访问控制方法的基础上，详细分析了文献[1]和文献[2]中利用密码技术实现层次访问控制的机制，指出了它们的优缺点。更重要的是，提出了一种新的简单而有效的利用密码技术实现层次访问控制的机制．通过与文献[1]和文献[2]中机制的比较，方案在存储和计算复杂度等方面都具有优越性。

英文摘要：

This paper analyzes the schemes of [1] and [2] based on the research of access control methods,which propose hierarchical access control methods using cryptosystems,and sets forth relative merits of each method.More importantly,we present a simple yet powerful approach for hierarchical access control using hybrid cryptosystems in this paper.The comparison to the existing two schemes shows that our scheme is more superior to them in both storage and computational performances.