Code Security in .Net

Question

I wrote a program and sent the compiled file to my friend. but after an hour, he sent me the code of that! How did he do that. And how can i prevent it? is this problem just in .net?

Answer 1

It can be done with reflector. If you want make it difficult for people to understand the code, you have to ofuscate it (there are tools to do dat, like dotfuscator).

I don't know if it's a .NET only problem...

Answer 2

Use an obfuscation tool like http://en.wikipedia.org/wiki/Dotfuscator.

Answer 3

ILSpy (http://wiki.sharpdevelop.net/ILSpy.ashx) will show you the IL and can transform it to c#. You can try obfuscation.

Answer 4

This is a design feature of .NET. Read the following for a better understanding.

Thwart Reverse Engineering of Your Visual Basic .NET or C# Code