给出了一种基于信息熵的隐通道能力分析方法。该方法首先利用无干扰分析法分析隐通道,得到系统状态转换分布特性,然后引入信息熵,进而推导出隐通道能力表达公式。该方法能较好地对隐通道能力进行定量分析,不仅可以对隐通道能力的大小进行计算,还可以分析隐通道能力的影响因素。最后,给出了存在于多级安全数据库中的一种隐通道,并用该方法分析计算了该隐通道的能力。
This paper presented a method based on information entropy to analyze the capacity of covert channels. Built upon noninterference, the method was firstly used to calculate the covert channel capacity, then to analyze the factors that had an impact on this quantity. Finally gave an example of the capacity calculation for covert channels in a multilevel secure database.