Abstract: It is the most important that building a consistent mandatory access control mechanism under the network environment with the requirements of information system level protection and network system security. This paper makes a further research on access control mechanism in information systems under network environment, puts forward the concept of the active label library, establishes a kind of access control marking method of supporting active label and proposes a nested index structure named EB+tree supported nodes extension on the basis of B+tree. The EB+tree forms a kind of multiple search tree which can express various label classification and constructs a label tree which is suitable for the application of access control mechanism. Thereby, the research gets a new type of access control mechanism which has validity, consistency and scalability.

Key words: access control, active label library, label tree, label forest

摘要： 依据信息系统等级保护以及网络化系统整体安全保障的要求，建立一个网络环境下全程一致的强制访问控制机制是至关重要的。针对网络信息系统的访问控制机制进行了深入的研究，提出了活动标记库的概念，建立了一种支持活动标记的访问控制标识方法，并且在B+树的基础上提出了一个支持节点扩展的嵌套索引结构——EB+树，形成了一种能够表达多种标识分类的多路查找树，构建了适用于访问控制机制的标记树，从而得到了一种具备有效性、一致性和可扩展性的新型访问控制方法。

关键词: 访问控制, 活动标记库, 标记树, 标记森林