Question

I want to avoid my program being simple to have the license-verifier part removed from.

I don’t want to use a commercial obfuscator because:

1. Of the cost. And though they can do a better job than I – they
   too don’t make it impossible to crack, just harder.
2. It seems that sometimes obfuscators cause bugs in the generated
   code.

Obviously, I will be keeping an un-obfuscated copy for maintenance.

Answer 1

I once had to hide a license verifier in code that the customer could modify. Conceivably, they could have removed it if they knew where to look. Here are some tricks that I used at the time.

1. Give your verifier classes, assembly names, and variable names that look like they actually do something else.
2. Call the verifier from multiple parts of the code.
3. Add a randomizer to the call for verification so that sometimes it runs, and sometimes it doesn’t. This will make it harder to know where the verification code is actually coming from.

I should add that all of this is defeatable and could cause serious maintenance headaches, but in my particular scenario it worked.