How to avoid being blamed on cheating?
I doubt that this would be a problem, provided that you don't cheat. But your work will probably be put through a plagiarism checker and get a score. How that is handled is up to the instructor. 

But if you really need assurance, then do the work under the eye of a mutually trusted individual who will attest to your following the rules. A proctor, in other words. 

Some people need such assurance, I think, perhaps because they aren't naturally trusted for some reasons. But for most people it isn't needed. Paranoia isn't essential in normal relationships. Cheating, when caught, is usually pretty obvious.