Covert Flow Graph Approach to Identifying Covert Channels
In this paper, the approach for identifying covert channels using a graph structure called Covert Flow Graph is introduced. Firstly, the construction of Covert Flow Graph which can offer information flows of the system for covert channel detection is proposed, and the search and judge algorithm used to identify covert channels in Covert Flow Graph is given. Secondly, an example file system analysis using Covert Flow Graph approach is provided, and the analysis result is compared with that of Shared Resource Matrix and Covert Flow Tree method. Finally, the comparison between Covert Flow Graph approach and other two methods is discussed. Different from previous methods, Covert Flow Graph approach provides a deep insight for system’s information flows, and gives an effective algorithm for covert channel identification.