A 213-foot luxury yacht veered off course while cruising in the Mediterranean Sea this summer after a radio navigation research team led by global positioning systems expert Todd Humphreys of the University of Texas Austin built a custom-made device capable of overriding the ship’s GPS receivers with spoofed signals.
Spoofing, according to the UT Austin Department of Aerospace Engineering and Engineering Mechanics at the Cockrell School of Engineering, is a process through which an attacker creates a false civil GPS signal that more local and stronger than the satellites that transmit civil GPS signals. In this way, the attacker can compromise GPS recievers, making them believe that the fals GPS signal is indeed the legitimate one.
The researchers claim that the GPS spoofing device they created is the first such openly acknowledged tool of its kind.
Holding a blue box roughly the size of a suitcase and standing onboard the White Rose of Drachs super-yacht as it travelled through international waters from Monaco to Rhodes Greece, graduate students Jahshan Bhatti and Ken Pesyna aimed the spoofing device in the direction of the vessel’s two GPS antennae. The blue box transmitted a subtle collection of fake civil GPS signals that eventually overwhelmed the ships GPS systems and gained complete control of its navigational course.
The process did not trigger any alarms nor were the fake signals in any way distinguishable from the real ones. In other words, a potential attack of this kind would be completely unnoticeable to the crew of a modern ship.
“With 90 percent of the world’s freight moving across the seas and a great deal of the world’s human transportation going across the skies, we have to gain a better understanding of the broader implications of GPS spoofing,” said Humphreys. “I didn’t know, until we performed this experiment, just how possible it is to spoof a marine vessel and how difficult it is to detect this attack.”
Specifically, after it took control of the vessel, the research team tricked the yacht’s GPS systems into believing that it had moved slightly off course. When these systems are made aware of a variation from a ship’s intended path, the crew corrects the variation, realigning the boat so that it is back in the correct position on the correct path. Of course, the crew was actually moving the ship off of it’s intended path, but an electronic chart in the cabin that is part of the White Rose of Drachs’ GPS system showed the ship moving in the proper direction on a fixed line.
“The ship actually turned and we could all feel it, but the chart display and the crew saw only a straight line,” Humphreys said.
In the end, the researchers had compelled the ship onto a parallel path hundreds of meters from the correct path.
Humphreys and his team claim that their spoofing device has implications that reach far beyond altering the navigation course of a privately-owned, $80 million super-yacht. In fact, just last year Humphreys led a team of researchers who managed to perform a similar GPS hijack on an unmanned aerial vehicle. They believe that this sort of GPS spoofing is a security vulnerability that the entire transportation industry is going to have to address.
“This experiment is applicable to other semi-autonomous vehicles, such as aircraft, which are now operated, in part, by autopilot systems,” Humphreys said. “We’ve got to put on our thinking caps and see what we can do to solve this threat quickly.”