Code Obfuscation Based on Inline Split of Control Flow Graph

Control flow graph is an important concept in the field of program analysis, which represents the source program in the form of graph. On the control flow graph, we can easily analyze the predecessor and successor relationship among basic blocks. This paper we inline the functions in the original program and outline the inlined program randomly to form outline functions. Therefore, we convert the intra-procedure basic block jump to an inter-procedure function call, which hides the basic block jump relationship in the process and obfuscates the function boundaries. In order to further increase the intensity of obfuscation, a bogus function similar to the outline function is added, and the bogus control flow is added in combination with opaque predicates simultaneously. Based on the above work, this paper proposes an obfuscation algorithm which converges and splits the program control flow graph. We utilize the commonly used cryptographic hash algorithm as the test set, and verify the feasibility and effectiveness of the obfuscation algorithm.