The most ubiquitous way between the world and the geospatial domain is through location-based technologies such as GPS and other GNSSs that power and support transportation, communication, and logistics around the world. This component of our invisible infrastructure is deeply embedded in our daily lives in ways we don't usually think about, except when we expect our ability to navigate to be accurate and instantly available. Undermine system reliability? Play with GPS? These are battle words.

Yet it happens and more frequently. The 30 or so GPS satellites themselves are not as vulnerable to interference as the signals they send out and the units that receive them. For example, it might seem like a good idea to create a quiet zone by blocking incoming calls, messages, and Wi-Fi in an area, but jamming those signals puts many other systems — like GPS — at risk. collaterals.

The signal jammer is a simple, but less elegant approach to disrupting the GPS signal. Its more complicated and sophisticated cousin, GPS spoofing, is also becoming more accessible, both technically and financially. Spoofing works by sending fake signals to a GPS receiver that mimic those sent by real satellites. The low signal strength of these fakes was a problem in the past, but new technologies have allowed the signals to become strong enough - and more similar to the real ones - that it's possible for the receiver to start tracking the fakes on the les. true. As David Last, former president of the UK's Royal Institute of Navigation, recently put it: "The signal jammer only causes the death of the receiver, spoofing makes it lie."

Todd Humphries, an engineering professor at the University of Texas at Austin, explains it well in his 2012 TEDx talk. In the video, he shares footage of how he made the little flashing blue dot on his cellphone's map - the universal "you are here" symbol icon - begins to drift away from his home, where he and his phone actually are. sitting still. Since then, he and his research team have done more than just these home demonstrations. In 2013 they tested their spoofing technologies on a 200ft yacht in the Mediterranean (with the full cooperation and awareness of the ship's crew) and digitally manipulated the ship to adjust its directional heading as a "correction" that was actually a complete misdirection. The ship's autopilot simply followed its own protocols to make the adjustment, not realizing that the incoming signals were wrong.

Larger vessels are just as vulnerable to these manipulations. In 2017, a tanker in the Black Sea had its navigation system indicate that it was suddenly in a completely different and unlikely place: at an airport 30 kilometers from its actual location at sea. ships were affected by this temporary attack, which Russians are now believed to have experimented with new approaches to cybersecurity breaches. GPS signals are routinely jammed in areas immediately around the Kremlin in Moscow, but this Black Sea issue was the largest real and successful spoofing effort known to date.

Some GPS spoofers have more innocuous intentions, such as trying to trick fellow Pokémon GO by simulating movement. But really, there are more ways to cause harm than good with these abilities. Virginia Tech's Curtis Zeng and his colleagues managed to lower the barriers even further by creating a successful spoofing system that only costs a few hundred dollars. With this inexpensive system in place, they were able to insert fake manipulated signals into the navigation routes followed by volunteers in a simulated driving situation. The attacker does not modify the original destination, but instead manipulates the user's real-time location (now a "ghost" location) on the map. The navigation system will recalculate a virtual fake route from the phantom location to the original destination, a route that would be physically feasible for the user to travel in the real world. Ideally, this wouldn't trigger the telltale "recalculation" warning, depending on whether the ghost location is on or off the original navigation route. Drivers continue to follow navigation instructions, but are now on a new route planned by the attackers.

Even trickier, Zeng and his colleagues managed to swap fake map layouts to further keep drivers in the dark. With these “ghost” maps in place, nearly all drivers in this study naively continued to follow directions that had been altered to arrive at false destinations. According to Zeng, “users tend to rely heavily on navigation systems in unfamiliar areas rather than learning the map and planning old-fashioned routes. It is (already) difficult for them to drive, follow navigation instructions and intersect with the surrounding environment at the same time. Moreover, few users understand how navigation systems work and how hackers can manipulate them. Many users have also experienced brief navigation malfunctions in real life, so a quick 'beep' in the system will not alert them (of the changes made). »

Tech-smart people are figuring out how to do it for nefarious reasons and other tech-smart people are working to stop them, or at least give us more of a chance for better results. A group of Irish electrical engineers recently documented ways in which they could successfully obtain multi-frequency spoofed GPS signals with inexpensive and readily available equipment, to show that it could be done (multi-frequency had been deemed unfeasible) and to continue to keep conversations active. Overestimating and underestimating adversaries' abilities are both counterproductive activities.

Efforts involving multiple strategies and tactics are underway by researchers, the public sector, and the federal government to combat the problems. What several of them have in common is that they strive to make the global navigation system less dependent on only GPS signals and their associated timestamps. These atomic clock enabled timestamps are considered so reliable that they are reliable for countless processes. At Clemson University, engineers are experimenting with a technique that regularly samples actual GPS signals and tags them to confirm their validity. Other users' devices can automatically compare those issued by Clemson with those their devices collect. This does not prevent spoofing, but it does notify the end user if their signals are compromised. Meanwhile, other researchers are going further and developing ways to fix compromised signals. Other approaches taken by private companies are to have navigation systems ready to receive signals from alternative sensors, such as mobile phone networks or commercial satellites, when the GPS signals are detected to have irregularities. These various strategies may not seem coordinated, but one organization that stays on top of the issue is the Resilient Navigation and Timing Foundation, a group that is involved in the situation on many global fronts.

We are faced with the jammer and impersonation that can be accomplished successfully by small players building cheap contraptions in their basements, and larger players, with bigger pockets and expertise depths, who may work on behalf of foreign governments. Really, this is all part of a bigger problem: the GPS system as a whole has too little redundancy and too many potential leaks that can be compromised too easily. One way forward is to simply have more GPS satellites in the collection as quickly as possible and produce new receivers designed with as many cybersecurity countermeasures as possible. We celebrate the open GPS system that gives us innovative and independent ways to operate location-based goods and services, but that's clearly a mixed blessing.