In the news this week, we have a case of life imitating Hollywood.
In Tomorrow Never Dies, Bond's nemesis-of-the-week spoofed a GPS signal to send a British warship into Chinese waters, while its captain and crew thought it was still on the right side of the border. Now, a University of Texas team has (with the skipper's permission) done exactly the same thing to a superyacht cruising the Med.
Engineering professor Todd Humphreys and his students put together a little rig that monitors the real GPS signals and, on command, adds a perfectly matched- and slightly more powerful- fake GPS signal, with the timings tweaked to create a slowly accumulating offset. As the GPS reported position on the ship's receivers drifts away from the intended course, the autopilot or the helmsman compensates to put the reported position back on track. The ship's true course is now under the control of the attacker. Here’s how it works [Youtube]:
We're not likely to see this attack in the wild just yet, but it does reinforce an important point: You should never rely on any single source of information for all of your situational awareness. A GPS fix is just one data point, to be used along with visual bearings, radar, celestial fixes, depth soundings and whatever other tools may be available. It should never be trusted on its own.