子程序花指令模糊变换逻辑一致性研究  

Research on Logic Consistency of Junk Code Transformation within Sub-function

作　　者：孙国梓[1,2] 陈丹伟[1,2] 蔡强[1,2] 

机构地区：[1]南京邮电大学计算机学院,南京210003 [2]南京邮电大学计算机技术研究所,南京210003

出　　处：《计算机科学》2009年第8期89-91,200,共4页Computer Science

基　　金：国家科技攻关项目(2004BA811B04;2007BAK34B06);江苏省高校自然科学研究计划项目(05KJD520150)资助

摘　　要：花指令模糊变换是代码模糊变换策略中的一种有效方法。在分析现有花指令加密方法的基础上,提出一种子程序花指令模糊变换方案,并利用形式化方法对其进行描述。通过研究子程序花指令模糊变换各种形式化的定义,推导出若干引理,从"XOR及CMP扩展"、"伪分支构造"、"JNE后加花指令"等3个方面加以形式化的证明,使得经上述子程序花指令模糊变换的程序具有与原程序相同的逻辑性。最后,以代码模糊变换评测标准对该算法的效果进行了详细分析。Junk 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 judgrnent, the paper gave the result of the algorithm in detailed analyzing.

关 键 词：代码模糊变换 逻辑一致性 花指令 反汇编 

分 类 号：TP311.53[自动化与计算机技术—计算机软件与理论]