How do I prevent managed dll from reverse engineering C#

Question

The problem is that my dll deals with encryption and the key is stored in constant variable. I want the key to be difficult to get. I understand that there's no way to hide it completely, but I hope there's a way to make it difficult to get the key. What could you suggest?
Thank you for your help!

Answer 1

What you are after is specifically tool that is capable of doing "String Obfuscation"

This free tool does it well http://www.ntcore.com/phoenix.php