Protect .NET code from reverse engineering?

Question

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,

Answer 1

Just to add a warning: if you are going to use obfuscation, check that everything still works! Obfuscation might change things like class- and method-names. So if you use reflection to call certain methods and/or classes (like in a plugin-architecture) your application could fail after obfuscating. Also stacktraces might be useless to track down errors.