基于行为的结构化文档多级访问控制

摘要

针对当前云计算环境中因缺乏多级安全机制而使结构化文档容易产生信息泄露和非授权访问等问题,提出基于行为的多级访问控制(action-based multilevel access control model,AMAC)模型并给出策略的形式化描述.利用信息流中的不干扰理论建立AMAC不干扰模型,并证明AMAC模型中多级访问控制策略的安全性.与已有访问控制模型的比较与分析表明,AMAC模型既可以利用角色、上下文和用户访问行为以提高访问控制策略的灵活性,还可以依据用户,用户访问行为和结构化文档的安全等级实现多级安全机制.%Cloud computing is a promising computing paradigm which has recently drawn extensive attention from both academia and industry.Meanwhile,structured document plays a vital role as information carrier in cloud computing.Therefore apparently,secure access to structured document is a key technology for the quality control of cloud services.In order to prevent information leakage and unauthorized access to the structured document,which is a common problem caused by lack of the multilevel security mechanism in current cloud computing environment,we propose an action-based multilevel access control model (referred to as the AMAC) and provide a formal description of access control policies.In our AMAC model,we employ noninterference theory in the information flow to establish AMAC noninterference model,and prove the security of multilevel access control policies in our AMAC model.Comparison and analysis with the existing access control models demonstrate that the AMAC model not only improves the flexibility of access control policies on the basis of roles,contexts and access actions,but also realizes multilevel security mechanism in terms of the security levels of the user,the access actions and the structured document.