how encrypt an executeable file and make that encrypted file executeable without using extra file for decryption?

Question

how can we encrypt an executeable file using c# and make that encrypted file still executeable without using extra file for decryption?
mean the decryption methods shuold be inside file.
how can i write something like that with c# language?

thanks in adavance

Answer 1

Storing encrypted data on clients machine and having it decrypt automatically means that you will have to store decryption key on that machine as well. This means that you can't effectively protect data and provide it to user. Such encryption is only used to slow down user from tampering with the data as time is needed to recover decryption key and algorithm.

If you want to encrypt code of the executable itself, to prevent user from tampering with it, this is a very very complex topic. It's only matter of persistence and time. You will not get an answer to such question in one StackOverflow post. You'll have to study PE and .NET file formats, operating system internals regarding executable loader as well as mscor*.

If you need to store some data

• choose some encryption algorithm and encrypt your data into a file (see this question )
• add encrypted file to your c# project as embedded resourse
• in runtime access this file (see this question ) and decrypt it (already discussed in first point)