You are not going to find a program that will make your copy "copyproof"......
$ony and every other manufacturer in the world has been trying for years........
A human invents the protection, and a human will break it....
The easiest way to solve your problem is to quit making backups for your so-called friends......
Ghosthacker supplied
this link in another post......
Maybe you can use this to make it a little harder for them to copy...