Drones, the unmanned aerial flying vehicles, have become a major part of modern warfare. Researchers at the University of Texas’ Lab have successfully demonstrated that a drone with an unencrypted GPS system can be taken over by a person owning a GPS spoofing device.
Using only $1000 worth of equipment, one can easy exploit vulnerabilities of unencrypted GPS signals.
While the powerful military drones used overseas use encrypted GPS signals, the ones in the United States rely on signals from open civilian GPS, which makes them vulnerable to GPS “spoofing.”
By Spoofing GPS signals, it is possible to gather enough information that makes it possible to take over the Drone. To elaborate, by the transmission of matched-GPS-signal-structure interference in an attempt to commandeer the tracking loops of a victim receiver and thereby manipulate the receiver’s timing or navigation solution, hackers can transmit its counterfeit signals from a stand-off distance of several hundred meters or it can be co-located with its victim.
Hacking the Drone
To commence the attack, the spoofer transmits its counterfeit signals in code-phase alignment with the authentic signals but at power level below the noise floor. The spoofer then increases the power of the spoofed signals so that they are slightly greater than the power of the authentic signals. At this point, the spoofer has taken control of the victim receiver’s tracking loops and can slowly lead the spoofed signals away from the authentic signals, carrying the receiver’s tracking loops with it.
Once the spoofed signals have moved more than 600 meters in position or 2 microseconds in time away from the authentic signals, the receiver can be considered completely owned by the spoofer.
Although our spoofer fooled all of the receivers tested in our laboratory, there are significant differences between receivers’ dynamic responses to spoofing attacks.
Are we Under Threat?
After the research experiment was conducted, it was noticed immediately by the U.S. government:
“DHS is attempting to identify and mitigate GPS interference through its new ‘Patriot Watch’ (pdf) and ‘Patriot Shield’ (pdf) programs, but the effort is poorly funded, still in its infancy, and is mostly geared toward finding people using jammers, not spoofers.”
The only way out is to work for hardening of GPS systems used in drones before they expand further into our worlds.
To be honest, this GPS flaw affects almost anything that flies ove head: Aircraft, ship, or vehicle navigation systems that feature unencrypted GPS systems. This technique may even be able to bring down a smart grid (pdf) or financial market.
Securing the UAVs
AUVSI is the world’s largest non-profit organization devoted exclusively to advancing the unmanned systems and robotics community. The provie following statements for Ensuring the Safe Use of Unmanned Aircraft:
“The unmanned aircraft systems industry is committed to the safe and responsible integration of unmanned systems into the national airspace. We are already in communication with a variety of stakeholders to ensure unmanned aircraft are integrated safely so we can unlock the tremendous potential of this technology to enhance public safety, advance scientific research and otherwise benefit society, all while potentially creating thousands of jobs.
“‘Spoofing’ or otherwise tampering with GPS has dangerous implications for any technology which depends on it for guidance, whether it is manned or unmanned aircraft, your cell phone or your car. In fact, commercial airliners are relying more and more heavily on GPS signals to locate the runways at airports and, with the advent of the next generation air traffic control system, all aircraft – manned and unmanned – will rely on GPS for navigation.
“The industry is well-aware of so-called ‘spoofing’ and is already advancing technologies, such as SAASM – Selective Availability Anti-Spoofing Module – to prevent it. This technology is already in use by the military to thwart GPS spoofing abroad and we expect it will transition to civilian unmanned aircraft in the coming years to protect aircraft flying in the national airspace. Meanwhile, some unmanned aircraft also have alternate navigation systems, such as radio links and backup inertial systems, which provide redundancy to GPS.