A Method Of Covert Channel Detection Based On Static Analysis

Based on summarizing covert channel's analysis methods and current research background, the paper has resolved the problem that the work of information flow analysis in system source code is automated; and organized the information flows using a graph structure called an information flow graph, provided the research idea that implemented a covert channel detection framework based on static analysis.Firstly, the paper discusses the definition of covert channel, and analyses the pros and cons of existing covert channel methods, according to them, the paper presents the design idea and scheme of the covert channel detection framework, which includes information flow generation and covert channel detection. Secondly, in order to obtain the information flows in source code, C/C++ statements are divided into two kinds of simple statements and compound statements, and information flow rules are defined for each kind. At the same time, as C/C++ language flow-sensitive character, the paper also defines flow-sensitive statement information flow override rule and derivation rule, as a complement to the information flow rules. Finally, the paper presents three algorithms:the first one can be used to get the information flows, the second one can be used to filter the information flows, and the last one is used to construct the information flow graph. With the help of the properties of covert channel and information flow graph, the paper proposes the covert channel reverse iteration detection algorithm.With the help of this framework, covert channels in source code can be detected more accuracy.