I would like to know if it is possible to do this through code or if there is any economical software available (freeware would be great) that can do this.
We would like to make certain PDF files available for sale. When the customer completes the formalities to purchase the PDF online right after his credit card is validated, we would like to display the link to the PDF file to the customer such that clicking on the link would allow the user to view the file. However, the link would have to be encrypted and it would have to be made available for one-time use only so that the link cannot be shared with anyone else.
Does anyone know how this can be done.