Obfuscation is one way, but it can’t protect from breaking the piracy protection security of the application. How do I make sure that the application is not tampered with, and how do I make sure that the registration mechanism can’t be reverse engineered?
Also it is possible to convert a C# application to native code, and Xenocode is too costly.
C# provides lot of features, and is the ideal language for my code, so writing the whole codebase again in C++ is out of the question.
Secure certificates can be easily removed from the signed assemblies in .NET.