General Method of Program Code Obfuscation

Obfuscation of machine code programs is a form of protection of programs' code against unauthorized reading. The problem of obfuscation is quite fresh, because first papers connected directly to obfuscation appeared only few years ago, yet some advanced publications can be already found. We reviewed them, describing in details most important papers of Christian Collberg and Chenxi Wang.

We proposed a formal model of program based on the analysis of changes in the usage of computer's resources utilized by the program. The model appeared to be useful for development of obfuscation methods working on the low level of programming. We showed that obfuscating transformation has some interesting properties and proved, that for machine programs it is possible to create a single-pass algorithm of obfuscation. Describing own classification of obfuscating transformations we described different methods of obfuscation from the low level point of view. Obtaining results of research on typical properties of structure of today's computers' programs we created an efficient method of redundant code generation, required during the process of obfuscation. On the base of theoretical analysis and experience of another scientists we proposed a basic algorithm of machine programs obfuscation, which was implemented for the RISC and CISC type processors.

To estimate efficiency of the obfuscation process we proposed three analytical methods of quality measurements and results of empirical research. We created three algorithms of machine programs' complexity measurement. For the implementation we showed results of quality measurements, performed using analytical and empirical methods. The empirical measurements were done on three different groups of programmers. From the final results it can be concluded, what should be the form of an algorithm of obfuscation, giving almost one hundred percent safe protection against unauthorized analysis. In the final conclusions we estimated values of parameters of an obfuscation process, giving such good efficiency.