Research on Logic Consistency of Junk Code Transformation within Sub-function
Qiang Cai · 2009
code transformation is an effective approach for the code obfuscation.Based on the analysis of current junk code strategies,the paper proposed a novel junk code encryption algorithm within sub-function and described the algorithm using formal language.With formalization method,the paper researched how to prove the logic consistency of junk code transformation within sub-function.We deduced some important lemmas after researching the formal definition of junk code transformation within sub-function.With these lemmas,the paper proven from three aspects(XOR and CMP Expand,Pseudo Embranchment Construction and Junk Code after JNE) that the program transformed by junk code algorithm within sub-function has the same logicality with its original one.At last,with the standard of the code-obfuscation's judgment,the paper gave the result of the algorithm in detailed analyzing.