One solution for protecting PHP source code

Protecting PHP scripts from unwanted using, copying and modifications is a vast problem today. Present solutions on source code level are mostly working as obfuscators, are free, and are not providing any serious level of protection. Solutions that are based on encoding opcode are more secure but are commercial and require closed-source proprietary PHP interpreter's extension. Furthermore, encoded opcode is not compatible with future versions of interpreters which involve re-buying encoders from authors. Finally, if extension source-code is compromised, all script encoded by that solution are compromised too. In this paper we present a novel model for free and open-source PHP script protection solution.