Encrypting my WordPress PHP files

I am interested in teaming up with a designer to create WordPress based site. However I want to protect my code as it will have a lot of valuable customisations in it, so that he cannot just steal it and use it for another client without involving me. Is this possible and what is the best way to do it? Thanks.

Over reaction…You do not need to encrypt your code. Most of it is Wordpress anyways. Seriously…If you do not trust the individual why are you giving this individual access in the first place? It makes no sense.

Zend Guard
IonCube
SourceGuardian

And there are more encoders available…just google them.