Abstract: A system for transmitting a database or other software over a communication link, such as the Internet, which prevents unauthorized use. In order to prevent such unauthorized use, the customer's equipment, such as a GPS unit, is provided with a unique software key. The updated database is ordered over the communication link by providing the unique software key and may include electronic payment information. The database is encrypted, for example, as a function of the unique software key and transmitted over the communication link in encrypted form along with an upload program. The upload program only allows the encrypted database to be uploaded into a unit with a matching software key. As such, the system allows updated databases to be transmitted rather quickly and easily over a communication link while preventing unauthorized use.