Utilización de excepciones para implementar predicados opacos en técnicas de ofuscación de código intermedio

Microsoft’s .NET Framework, and JAVA platforms, are based in a just-in-time compilation philosophy. Software developed using these technologies are executed in a hardware independent framework, which provides a full object-oriented environment, and in some cases allows the interaction of several components written in different programming languages. This flexibility is achieved by compiling into an intermediate code which is platform independent. Java is compiled into ByteCode, and Microsoft .NET programs are compiled into MSIL (Microsoft Intermediate Code). However, this flexibility comes with a price. It is really easy, with tools available for free in the web, to decompile this intermediate code and obtain a working, readable version of the original source code. Of all techniques developers can use to protect their intellectual property, obfuscation is the most accepted and commercially available one. In the present work, we propose the use of try-catch mechanisms available in .NET as a way to improve the quality of one of the building blocks of obfuscation: opaques predicates.