Last month, Todd Humphreys, assistant professor in the Department of Aerospace Engineering and Engineering Mechanics, presented at TEDx about how the GPS dot will fundamentally re-order our lives. Below, Humphreys shares his script from his talk, and introduces the dark — and bright side — of GPS dots.
What's the predictable endpoint of the trend toward ever cheaper, ever smaller and ever more sensitive GPS? It's the GPS dot — a GPS tracking device first featured in the movie "The Da Vinci code" and now moving inexorably from fiction to non-fiction. The GPS dot will fundamentally re-order our lives. We'll buy dots in bulk and stick them on everything we own worth more than a few tens of dollars.
But there is a dark side to the dot.
Did you know that it's not illegal to track your family, your friends, or even your ex-girlfriend/boyfriend with a GPS dot? The lack of effective legal means of protecting ourselves from an invasion of GPS dots will lead to use of subversive tools for protecting our personal space, such as GPS jammers and spoofers. A rise in the use of these illicit tools has the potential to wreak havoc on the "good" GPS receivers — those built into our critical systems and infrastructure. The result: A looming showdown between privacy and GPS integrity.
TEDx Austin Script
By Todd Humphreys
Something happened in the early morning hours of May 2, 2000 that had a profound effect on the way our society operates. Ironically, hardly anyone noticed at the time. The change was silent — imperceptible unless you knew exactly what to look for. That morning, United States President Bill Clinton ordered that a special switch be thrown in the orbiting satellites of the Global Positioning System. Instantaneously, every civilian GPS receiver across the globe became 10 times more accurate, going from errors the size of a football field to errors the size of a small room.
It's hard to overstate the impact of this improvement in accuracy. Before that switch was thrown there were no in-car navigation systems giving turn-by-turn directions, because back then, civilian GPS couldn't tell you what block you were on, let alone what street. For geolocation, accuracy matters.
Things have only improved over the last decade. With more ground stations, better algorithms, and better receivers, stand-alone GPS can now tell you not only what street you are on, but what part of the street. This level of accuracy has enabled a firestorm of innovation. In fact, many of you navigated here with the help of your TomTom or your smartphone. Paper maps are becoming obsolete.
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We're now on the verge of another revolution in geolocation. What if I told you that the two-meter accuracy that our iPhones and Garmins currently give us is pathetic compared with what we could be getting? For some time now it has been known that if you pay attention to the carrier phase of the GPS signals, and if you've got an Internet connection, you can go from meter-level, to centimeter-level and even millimeter-level positioning. So why don't we have this capability on our smartphones? Only for a lack of imagination.
Manufacturers haven't built this carrier-phase technique into cheap GPS chips because they're not sure what the general public would do with geolocation that is so accurate you could pinpoint the wrinkles in the palm of your hand. But you and I and other innovators can already see the potential of this next revolution in accuracy. Imagine, for example, an augmented reality app that overlays a virtual world to millimeter-level precision on the physical world. I predict that within the next few years, this type of hyper-precise carrier-phase-based GPS will become ubiquitous and cheap. And the consequences will be fantastic.
The holy grail, of course, is the GPS dot. Do you remember the film "The Da Vinci Code"? Here is Professor Langdon examining a GPS dot, a tracking device said to be accurate within two feet anywhere on the globe. But we know that in the world of non-fiction, this is impossible, right? For one thing GPS doesn't work indoors. For another, they don't make devices this small — especially when the devices have to relay measurements back over a network.
As it turns out, these objections were perfectly valid a few years ago, but things have changed. There has been a strong trend toward miniaturization, better sensitivity and reduced price.When you look at the state-of-the art for a complete GPS receiver, which is less than a centimeter on a side and more sensitive than ever, you realize that the GPS dot will soon move from fiction to non-fiction.
Imagine what we could do with a world full of GPS dots. It's not just that you'll never lose your keys or your wallet again — or your child at Disneyland — you'll buy dots in bulk and stick them on everything you own worth more than a few dollars. I couldn't find my shoes one recent morning and, as usual, had to ask my wife if she had seen them. But I shouldn't have to bother my wife with that triviality. I should be able to ask my house where my shoes are. Those of you who use Gmail remember how refreshing it was to switch from organizing your e-mail to searching it. The GPS dot will do the same for our belongings.
There is, of course, a flip side to the GPS dot. A few months back I got a phone call in my office. The woman on the other end of the line — we'll call her Carol — was panicked. An ex-boyfriend of Carol's from California had found her in Texas and was following her around. Now you might wonder at this point why she was calling me. So did I. But there was a technical twist to her case. This ex-boyfriend would show up at the most improbable times and the most improbable locations, and whenever he showed up, he had an open laptop. Over time, Carol realized that this ex-boyfriend had hidden a GPS tracking device on her car. She was asking for my help to disable it.
"Go to a good mechanic and have him search your car," I suggested. "I already have," she said. "He didn't see anything obvious. He said he'd have to take the car apart piece by piece." "Well then you had better go to the police." "I already have — but they're not sure it's harassment and they're not set up technically to find the device." "What about the FBI?" "I've talked to them too, same response." We then talked about performing a radio sweep of her car, but I wasn't sure this would work because some tracking devices only transmit when they're within safe zones or when they sense the car is moving.
So there we were. Carol wasn't the first, and certainly won't be the last, to be left with no escape from this kind of frightening invasion of privacy. In fact, as I looked into her case, I discovered to my surprise it's not clearly illegal for you or me to put a tracking device on someone else's car. The Supreme Court ruled last month that police have to get a warrant for prolonged tracking, but the law isn't clear about civilians doing this to one another. So it's not only Big Brother we have to worry about, but Big Neighbor.
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There is one very effective option Carol could have taken. It's called the Wave Bubble. It's an open source GPS jammer designed by Limor Fried, a graduate student at MIT. Limor calls it a "Tool for Reclaiming our Personal Space." You see, because with the flip of a switch, you create a protective bubble around yourself that drowns out all GPS signals. Limor designed it in part because, like Carol, she felt threatened by GPS tracking. She published her design on the Web. And if you don't have time to build your own Wave Bubble, you can just buy one. Chinese manufacturers now sell thousands of nearly identical devices on the Internet.
You're probably thinking the Wave Bubble sounds great, that it could come in handy if someone ever puts a tracking device on your car, but you should also be aware the Wave Bubble is very much illegal in the U.S. Why? Because it's not a bubble at all. Its jamming signals don't stop at the edge of your personal space or at the edge of your car, they go on to disrupt GPS receivers for miles around you. If you're Carol or Limor, or someone else who feels threatened by GPS tracking, it might not feel wrong to use a Wave Bubble, but in fact turning one on can be disastrous. Think about it: Say you're the captain of a cruise ship trying to make your way through a thick fog and some passenger in the back turns on a Wave Bubble. Your GPS navigation system goes blank. Now it's just you, the fog and whatever you can pull off the radar. Remember, they don't make or maintain lighthouses and foghorns anymore, and the only backup to GPS, a system called LORAN, was discontinued just over a year ago.
Our modern society has an almost blind reliance on GPS. It's built deep into our systems and infrastructure. Some call it the invisible utility. Turning on a Wave Bubble might not just cause inconvenience, it might be deadly.
But as it turns out, for purposes of protecting your privacy at the expense of general GPS reliability, there is something even more potent and even more subversive than a Wave Bubble. That is a GPS spoofer. The idea behind a spoofer is simple: instead of jamming the GPS signals, you fake them. If you do it right, the GPS device you're spoofing doesn't even know it's being fooled.
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So is this really possible? Could someone really manipulate a GPS receiver's timing and positioning just like that with a GPS spoofer? The short answer is yes. The key is that civil GPS signals are completely open. They have no encryption, they have no authentication. They are wide open and vulnerable to being spoofed.
Even so, up until recently nobody worried about GPS spoofing. People figured it would be too complex or too expensive for some hacker to build one. But I and a friend of mine from graduate school didn't see it that way. We knew it wouldn't be so hard, and we wanted to be the first to build one so we could get out in front of the problem and help protect against spoofing.
I remember vividly the week it all came together. We built it at my home, which meant I got some extra help from my three-year-old son, Ramon. The spoofer was just a jumble of computers and cables at first, though we eventually fit it into a small box. The Dr. Frankenstein moment — when the spoofer finally came alive and I got a glimpse of its awful potential — came late one night when I tested the spoofer against my iPhone. I had come to completely trust the little blue dot on my iPhone, and its reassuring blue halo. They seemed to say "here you are, here you are, you can trust me." So something felt very wrong about the world, it was almost a sense of betrayal — I could feel it in my stomach — when I saw this blue dot start from my house and go running off toward the north. Because ... I wasn't moving.
What I then saw in that moving blue dot was the potential for chaos. I saw airplanes and ships veering off course, with the captain completely unaware until it was too late. I saw the GPS-derived timing of the New York Stock Exchange being manipulated by hackers. You can scarcely imagine the mischief that someone could cause if he knew what he was doing with a GPS spoofer. And yet, the spoofer has one redeeming feature: it is the ultimate weapon against an invasion of GPS dots. If someone is tracking you, you can play them for a fool, pretending to be at work when you're really on vacation.
I am fascinated by this looming conflict between the need for privacy on one hand, and the need for a clean radio spectrum on the other. We simply cannot tolerate jammers and spoofers, and yet, given the lack of effective legal means of protecting our privacy from the GPS dot, can we blame people for wanting to use them?
My hope is that we can resolve this conflict with some yet undiscovered technical innovation. Meanwhile, grab some popcorn, because this is going to get interesting. Within a few short years, many of you will be the proud owners of a GPS dot. Maybe you'll have a whole bag full of them. You'll never lose track of your belongings. The GPS dot will fundamentally re-order your life. But will you be able to resist the temptation to track your fellow man? And will you be able to resist the temptation to turn on a GPS spoofer or a Wave Bubble to protect your own privacy?
As usual, what we see just beyond the horizon holds both promise and peril, and we wonder how it will all play out.
TEDx, a program of local, self-organized events that bring people together to share a TED-like experience. At a TEDx event, TEDTalks video and live speakers combine to spark deep discussion and connection in a small group. These local, self-organized events are branded TEDx, where x = independently organized TED event.
