Abstract: In the design and implementation of the current security systems based on BLP model, subject’s security label and access right inherit from the user’s. This may enlarge the access ability which violates the least privilege theorem and give the malious subject the chance to gain higher security label and more rights to steal and damage information. To solve this problem, the paper presents an improved BLP model based on user’s intention——IB_BLP model. In the new model, subject needs to get user’s intention to meet the least privilege theorem while accessing object.

Key words: Information security, BLP model, User intention

摘要： 在基于BLP模型的安全系统设计与实现中，其主体的安全标记与访问权限分别继承自登录用户的安全标记与访问权限，使得主体的资源访问能力过大，破坏了最小权限原则，使恶意进程能够进行大范围的信息窃取与破坏。针对上述问题，该文提出了一种基于用户意愿的改进BLP模型IB＿BLP模型，要求主体对于具有访问授权要求的客体的访问，必须遵循用户的操作意愿，使主体的权限最小化。

关键词: 信息安全, BLP模型, 用户意愿