Measuring the security of code obfuscation is difficult. A novel obfuscation transformation is in some cases only measured in terms of code expansion and speed, which are in fact only side effects of the transformation. A first step to define a security value to an obfuscation transformation could be having a look at what a cracker is able to reveal from an obfuscated program. This abstract first of all gives a short overview of existing techniques to obfuscate. Then, we describe existing techniques that can be used to deobfuscate, which were sometimes originally meant for other purposes, and new techniques which we are working on to deobfuscate.