Control Access to Filesystem with PHP

[cuteharez]

I previously posted here: http://stackoverflow.com/questions/3731171/controlling-access-for-trial-subscriptionSince this is a new question based on suggestions there, I thought I should start a new post. If this should have been an edit, please let me know for the future.I think the solution I'm going with to control access will be to upload a file and hash the name. The file will be in the format:/uploads/#############.pdfA link will be sent to subscribers. The first time they come to the site, they'll be asked to create a "pin" and a "hint" to remember. Then can then access a landing page to list their items via an email address/pin combo.My question is: I know I can control the access to the page that shows what items they can view, but is there a way to control the /uploads/[file] to only be download-able after some kind of programmatic check? I can't think of any way to do this....Thanks again.D.