Are there any legitimate programs that can actually encrypt PHP so others can't read the source if the file is distributed? There are so many programs that claim to do this, but each one I've seen can be decrypted easily. They have layers of encryption, but the source code can be seen by simply decrypting one layer at a time. Simply echo the final result instead of running it as code.

 

The ones that generate unique keys for each file do not help. The key itself must be somehow distributed with or in the PHP file. I haven't seen any methods to prevent a good programmer from eventually reaching the original source, even if it takes a while to do so.

 

Is it possible for me to protect my source codes if I sell scripts written in PHP?

Zend Encoder and ionCube are the two popular systems I know of, and I don't think they can be easily decoded.

 

It's probably not worth the trouble though. For a language like PHP, people will always want to meddle with the source, and unless you make an incredibly popular product, most people will buy it rather than pirate it. Heck, vBulletin isn't even source-encoded -- you could copy the source off SFN and use it elsewhere. If Jelsoft noticed they'd have your host shut the site down, though.