alternative to protecting files through http auth.

Is there no other way to protect your (non PHP) files than through authentication? I've been trying to set up a system that will protect files. Those trying to access the files would only be able to do so after entering their email address. So I set up a form that submits the email to my database. But then the problem is: how to access the files? I could just use http://username:password/test.com/test.jpg method, but then what would be the point of trying to protect the files in the first place? It would simply be the same as with holding the link to begin with. So is there an alternative to using http basic authentication to protect files? Or is there a simple way to authenticate the pages themselves without using something like Manuel Lemos' "PHP HTTP class"? Best Regards, Scott Taylor