基于随机插入策略的Java混淆器设计与实现

Design and implementation of Java obfuscator based on random-insert method

控制流混淆用于混淆程序的运行流程,从而防止对软件的逆向工程,但通常混淆后的程序在代码量以及执行时间方面都有较大增长。提出了随机插入混淆策略,采用分支插入算法和循环条件插入算法相结合,并引入了随机函数以限制代码的插入操作,从而控制代码长度的增长。使用BCEL设计并实现了基于Java字节码的控制流混淆转换工具,能够实现Java字节码的迭代混淆,且混淆结果具有一定的不可再现性。实验结果表明,该策略能够有效地控制混淆转换带来的性能过载,同时能够有效地防止逆向工程攻击。

Control code obfuscation is intended to prevent malicious reverse engineering of software by masking the program control flow. But the file size and execution time often increase intensively. Random-insert method is presented to solve the problem. Branchinsert and loop-insert are used in the method and a random function is introduced here to control the number of insert operation. An obfuscator is implemented using BCEL, which can obfuscate java byte code. Our experiments show that aided with the method, obfuscation is done efficiently with moderate increases in code size, execution times, while making the obfuscated code resilient to a variety of reverse engineering attacks.