混淆算法研究综述

首先对混淆算法的力量、弹性、执行代价和隐蔽性等性能及其度量作了介绍.随后对各种混淆变换作了简要的叙述和评论.混淆变换主要分为以下几种:第一,词法变换;第二,控制流变换,包括分支插入变换、循环条件插入变换、将可化简的控制流转换为不可化简的控制流,取消循环和控制流恶化;第三,数据变换,包括数组重构变换、变量重组变换、将静态数据转换为与程序相关的数据和数值变量混合变换;第四,类结构变换,包括类熔合、类分裂和类型隐藏.此外,对使用对象和别名的不透明谓词和利用并行技术构建不透明谓词进行了简介,并综述了对混淆算法的攻击方法以及混淆算法的应用.最后对反混淆和对混淆算法的攻击进行了总结,并提出了若干可能的研究方向.

Survey on Research of Obfuscating Algorithms

Measures of potency,resilience,stealth and execution cost are introduced at the beginning.Then a synopsis and a review of following categories of obfuscating transformations are given.The first is lexical transformation.The second is control flow transformations including branch insertion,extending loop conditions,converting a reducible flow graft to a non-reducible one,removing loops,deterioration of control flow and dataflow transformation.The third is data transformations including restructuring arrays,reconstructing variables,converting static data to procedural data and merging scalar variables.The fourth is class structure transformations including class coalescing,class splitting and type hiding.Furthermore,attacks against obfuscating algorithms and deobfuscation are summarized.Some suggestions about future work are proposed in the end.