script inactive if copyright is removed???

forcer

now i finally have enough scripts to publish on my site i would like it so people cannot remove a small copyright notice i added to the bottom of each script

<?php
//  DO NOT REMOVE THE COPYRIGHT(POWERED BY: ) NOTICE
	print "<center>";
	print "<strong>";
	print "<font size=\"1\" face=\"Verdana, Arial, Helvetica, sans-serif\">";
	print "Powered by:<br>";
	print "<a href=\"http://www.digitalbreeze.net\" target=\"_blank\">DB-Guestbook</a>";
	print "</font>";
	print "</strong>";
	print "</center>";
//  DO NOT REMOVE THE COPYRIGHT(POWERED BY: ) NOTICE
?>

this is the footer.php file thats added to the bottom of every script.

if this file is removed how can i make it say...

or something along those lines.

how can this be done

are there any tutorials on how to protect your scripts?

i sene a script before that if people removed the notice it contacted the hot telling them exactly who has removed it.

any help appreciated

AstroTeg

[rant]

I'm not sure its worth the effort since the user could just modify the PHP code so it doesn't send email or disable the script.

The other trick is you're printing a copyright notice on a web page which implies you own the copyrights to the look/feel of the page itself - which very much may be true, but if they modify the look/feel, you no longer have rights to the new look/feel, even though you are still printing the copyright. So the user may have an interest in having the copyright info removed (this is how osCommerce works - they own the copyrights to their theme and require the copyright to be displayed if you use the default them - but modify the theme and the printed copyright no longer applies).

Now what might make more sense is at the top of the PHP page you include your complete copyright notice commented out and say it must always appear there. That is very much valid since you wrote the code and removing it would imply they wrote all the code.

[/rant]

With the topic at hand, I'd probably look at using the md5 hashing algorithm to create a hash value of the footer. Store it somewhere and have a snippet of code check the footer every now and then and see if its hash value matches up with the stored value. If it doesn't, then there's been a change. Problem with this is if the copyright year changes or something minor changes, then the hash becomes invalid and you have to generate a new one. Not overly difficult to overcome, but something to think about.

Erkilite

if you look on zend.com they have a php encoder, but you will have to install the engine into the webserver (i think) to decode the page when being viewed. otherwise you can use a program that removes all excess white space making it very difficult to read.