With all of the different scripts that are being released they are all using different methods of encryption on there source code. Even though its encrypted there are still people out there that are decrypting them daily to steal and use illegally. What is the best form of php source encryption to use on software now a days to prevent files from being stolen? I am developing many plugins that are unique and know that they would be good use to some but I want to protect my php. What should I do? I already have a licensing service in place just need to know about encryption!
Most people acknowledge that some theft is inevitable and make their money via support or unlocking additional features - which involve a call back to your server.
create a business model in which the code is an incomplete part of the value of your offering. For example, sell product licenses along with access to some data you manage on your site, or license the product on a subscription model or with customer support.
ionCube has system for online encoding in case you don't want to buy the software: http://www.ioncube.com/online_encoder.php
What you need is code encryption. There are several tools available such as ionCube or Zend Guard. Keep in mind that PHP is by itself an interpreted language, so trying to protect your code has some disadvantages. One of the biggest is that the end user that wants to run your application has to have special software installed on the server that will be able to read the encrypted sources. However, installing proprietary software can be a meticulous process for some users.
ionCube is one of the requirements to run our scripts and so far we had only one client that could not install ionCube loader on their server. He moved to another hosting provider.