Hollywood loves the idea of digital cinema because it dramatically reduces the cost of distributing movies. Instead of transporting 35mm film in cans, the movies are broadcast electronically by satellite or cable. Encrypting the transmitted signal should stop unauthorised use, but this system of protection would collapse if a pirate stole a legitimate movie receiver.
Boeing has patented a method of improving security by equipping each receiver with a built-in GPS locator (US 2003/204739). When the receiver is installed at a cinema, the broadcaster makes a note of its location. Before a movie is broadcast, the transmitter interrogates the receiver…
