Files sharing is always a risk. However, the reason that the download links should be protected, is because if they are not, somehow SE might trace the page with the download links and then it will become really a public domain.
Instant Download Cart is a small but powerfull digital products cart that will allow you to:
Setup yourself your PayPal Details.
Upload your ptoducts
Use your own preferite images for the Add to Cart Buttons.
Upload your products just using your browser. The script will create for each product the necessary code to place in your pages.
It will verify the payment with PayPal.
Upon return to the site, it will display the download links for the products purchased.
It will "drag" from PayPal additional details about your customer (Name, email, country) and store them in the database.
Provide you, through the database interface, with full details about your sales and your customers (as explained above).
If you are interested, you can contact me through
my form.