I'm writing a software and going to sell it soon. I will provide all PHP files to buyer, but then he can open those files in php editor and edit them easily and I wouldn't like it. My question is: Is there any way to encrypt php files somehow and secure them from editing? Or at least make editing difficult? Free option would be the best, but if you know some commercial encrypting software, please share. I'm open for any ideas.
P.S. How can I secure mysql database in Wamp (this is less important, please answer mainly for question above)?