How do I make a Trial Download? Or a Secure Download?

need to create 3-day download and secure download for buyers

[jonpurgason]

I use Front page.
My question is how do I create a trial download that is non-printable/non-editable that will expire in 1-2 days? My trial download currently is in Acrobat, and is protected by a password, but that is it....and it can be viewed forever.
In addition, how do I protect the purchased version of the download so that it can not be transferred from computer to computer? Thanks!

[shady]

how do I create a trial download

The only way I can think, is to have a database driven system, which controls access.
The "actual" file would reside somewhere that was inaccessable directly from the web and the download script would make it accessable indirectly.

OSCommerce has this functionality built in, so it may be worth looking there.

how do I protect the purchased version of the download

Mmm, this is trickier. Personally, programs I release access the web, so when the program fires up, it checks a licensing database via myodbc, providing the target host is available (if not, it simply allows access for that session).
It is not foolproof and could probably be easily foiled using a firewall, but it has worked for me.

Other than this, I'm sure there are licensing packages out there, but then again, there is so much hacked software out there, I'm sure that "standard" approaches are fairly useless!

Regards
Shady!