The Global Position System (GPS) is being increasingly used for a variety of critical applications. These include public safety services (police, fire, rescue and ambulance), marine and aircraft navigation, cargo security, vehicle tracking, and time synchronization for utility, telecommunications, banking, and computer industries.
While people tend to think about GPS as being high-tech and thus high security, the fact is that the satellite signals used in most GPS applications are not secure. The civilian GPS signals—the only ones available to private industry and the vast majority of the federal government—are neither encrypted nor authenticated. They are thus easy to counterfeit, unlike the military GPS signals.