Description of the approach to development of the obfuscating compiler

Abstract

Nowadays protecting intellectual property rights for created software is very important because of many competing companies and ubiquitous piracy. The powerful technique for this protection is to obfuscate program code. This paper describes an approach for developing an obfuscation tool based on a compiler infrastructure. Using the compiler infrastructure is beneficial as during compilation we have the complete information about the compiled program for free and we do not need to solve problems like correct disassembling, new target support etc. We have formulated the efficiency criteria for an obfuscating technique: an obfuscation transformation should obfuscate both control flow and data flow simultaneously. The main feature of the described approach is using the set of transformations, which mask the various aspects of the obfuscated application. Together, this set provides the strong protection against the static analysis. Opaque predicates insertions, flattening and increasing indirection transformation are the most efficient transformations. Also we have formulated the compiler infrastructure requirements that need to hold for successfully implementing an obfuscating compiler using this infrastructure. The essential requirements are complied with LLVM (low level virtual machine) compiler infrastructure.