I don't think I've seen a php script that can't be decoded... So I'm thinking about selling my script, but I want to prevent it from being modified by anyone except me. What are my options?
yes you use this encoder and then your code cannot be modified zend guard and ioncube are the most popular
the above mentioned solutions are the best, but dont be fooled into thinking these cannot be broken, they can and if someone really wants to access it they will. is it purley so noone can edit it? or so noone steals the code? I sell plugins and toyed with encoding the code but in the end it adds another task and can cause issues in the code. if you really want to protect the script the only real way is to make the script reference scripts/functions on your own server. then noone can get at the code. but this has obvious downfalls (bandwidth, sets your server as a hacking target, etc)