Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×
United States Technology

Aviation Sector Sees No Fast Tech Solution To GPS Interference Problem (reuters.com) 108

Global regulators, aviation security specialists and manufacturers failed to reach an agreement on a quick technical fix to the problem of GPS spoofing near war zones, instead calling for better training of pilots to deal with the issue, Reuters reports, citing sources briefed on the talks. From the report: Airlines have been urging quick action after a series of incidents where navigation systems were disrupted to show a false location or wrong time, though aircraft flight controls remained intact. Spoofing might involve one country's military sending false Global Positioning System signals to an enemy plane or drone to hinder its ability to function, which has a collateral effect on nearby airliners.

GPS jamming and spoofing have grown worse in Eastern Europe, the Black Sea and the Middle East, according to industry group OpsGroup. GPS is a growing part of aviation infrastructure as it replaces traditional radio beams used to guide planes towards landing. The first international meeting bringing together the sector was held on Thursday in Cologne, Germany, organized by the European Union Aviation Safety Agency (EASA) and international trade group the International Air Transport Association (IATA). GPS interference "can pose significant challenges to aviation safety," and requires that airlines increase data-sharing on jamming and spoofing events, EASA and IATA said in a joint statement.

This discussion has been archived. No new comments can be posted.

Aviation Sector Sees No Fast Tech Solution To GPS Interference Problem

Comments Filter:
  • by packrat0x ( 798359 ) on Friday January 26, 2024 @03:05PM (#64190338)

    Supplement GPS with old fashioned radio beacons.

    Spoof a radio beacon?
    1 Its for commercial aviation.
    2 That's asking for an anti-radiation missle.

    • There was LORAN but that was shut down. Who needs land based radio navigation when you have GPS right?

      • Re: Radio Beacons (Score:4, Interesting)

        by LindleyF ( 9395567 ) on Friday January 26, 2024 @03:27PM (#64190398)
        VORs are still a thing. In the US at least, not sure about elsewhere. And some planes can still use NDBs. There are non-GPS solutions already. Besides, why would anyone think fixing GPS spoofing would be easy? If it were, it wouldn't be an effective military tactic.
        • by crt ( 44106 )

          The problem isn't just that GPS is failing - it's failing in a way that screws up INS systems as well (which are SUPPOSED to be the backup). There should be a technical solution to better decouple those two - right now they appear to be too tightly coupled in most designs (with the GPS re-initializing the INS constantly).

          • Re: Radio Beacons (Score:5, Interesting)

            by AmiMoJo ( 196126 ) on Saturday January 27, 2024 @11:30AM (#64192414) Homepage Journal

            There is already a solution. Add a Galileo receiver. The Galileo system includes verification of the received data, so it can't be spoofed, using public key crypto.

            If the check fails then assume the signal is spoofed or there is jamming, and fall back to other sensors.

            • There is already a solution. Add a Galileo receiver. The Galileo system includes verification of the received data, so it can't be spoofed, using public key crypto.

              If the check fails then assume the signal is spoofed or there is jamming, and fall back to other sensors.

              Authenticating signals is great against bored teens with SDRs playing around with GNSS simulators. When it comes to state actors in a war zone I'm not so sure this is going to stop spoofing. All you need to do to spoof location is preferentially delay RF signals so that they arrive at your target when you want them to. There is no requirement to modify the signals in any way.

              • by AmiMoJo ( 196126 )

                Replay attacks don't work.

                The Galileo system includes strict timing requirements, which mean that rebroadcasted messages will be rejected if they are delayed.

                The only known way to overcome that is if you are able to rebroadcast messages as the receiver starts up and handles the initial time sync. So aircraft in your own country, but not ones entering from outside the range of your spoofing.

                • Replay attacks don't work.

                  The Galileo system includes strict timing requirements, which mean that rebroadcasted messages will be rejected if they are delayed.

                  OSNMA while useful and certainly a step in the right direction does NOT prevent repeater spoofing. There is too much uncertainty in clock jitter, ionospheric delay..etc. for "strict timing requirements" to matter. Purpose built high energy amps are able to repeat weak signals in nanoseconds. A state actor can have high altitude aircraft or low orbit satellites perform spoofing.

                  The only known way to overcome that is if you are able to rebroadcast messages as the receiver starts up and handles the initial time sync. So aircraft in your own country, but not ones entering from outside the range of your spoofing.

                  More likely worst case given repeater based spoofing is the receiver doesn't work for a while and when it reacquires signal it ha

                  • by AmiMoJo ( 196126 )

                    Nanoseconds is too much. If the delay is enough to screw up positioning, the receiver will reject it. If you believe otherwise, show us the published research.

                    The current worst known attack requires the attack to start before the receiver starts up. If you have developed a novel new one, publish or get rich by selling it to Iran or something.

                    • Nanoseconds is too much. If the delay is enough to screw up positioning, the receiver will reject it.

                      This is ridiculous on its face. On the best of days GPS derived time sources have an uncertainty of several tens of nanoseconds. Propagation through ionosphere by itself adds up to a dozen nanoseconds of uncertainty to ToF.

                      If you believe otherwise, show us the published research.
                      The current worst known attack requires the attack to start before the receiver starts up.
                      If you have developed a novel new one, publish or get rich by selling it to Iran or something.

                      The people who designed these systems are well aware of these issues which is why they couple their solutions with a variety of supporting elements such as analysis of RF environment, receiver based atomic clocks, sensor fusion and bidirectional communication.

                      You don't have to take my w

                    • by AmiMoJo ( 196126 )

                      And yet, this is the best known attack against it: https://www.ion.org/publicatio... [ion.org]

                      I note that neither of your links provide a better attack than that one, which as I've said twice already requires catching the receiver in the startup phase.

                      There are no practical repeat broadcast attacks against Galileo. My understanding is that the Chinese system is likely to be just as robust.

                    • And yet, this is the best known attack against it: https://www.ion.org/publicatio [ion.org]...

                      From the summary of a "novel replay attack" given I don't have access to the paywall this seems to be something completely different from what I'm talking about and the reference I provided is demonstrating. My claim does not require exploitation of any design or implementation weakness however exploitation of such weaknesses would certainly make spoofing a lot easier and cheaper.

                      I note that neither of your links provide a better attack than that one

                      Saying you have a better exploit that makes the system even weaker than it would otherwise be doesn't help your case.

                      , which as I've said twice already requires catching the receiver in the startup phase.

                      Even under

            • If the check fails then assume the signal is spoofed or there is jamming, and fall back to other sensors.

              That's not a solution, that just tells you you have a problem. If it were so easy and accurate to use other sensors you wouldn't need any fancy anti-spoofing public key crypto, you could just do a comparison.

              A post below will tell you why "other sensors" are no good for modern aviation and why the aviation industry adopted GPS en mass.

      • There was LORAN but that was shut down. Who needs land based radio navigation when you have GPS right?

        And...what did they use to navigate before radio navigation?

        I'm old enough to remember when pilots carried large brief cases around full of maps and charts and the like.

        Are pilots no longer required to learn anything analog any longer?

        • As someone who was a land pilot, my job required me to go to remote locations all over south Texas and I would print up maps before I left because GPS was pretty useless down there. I still do it to this day when I travel somewhere I am not familiar with. And yes, I do have a bunch of physical maps also I carry.

          If it ain't broke, don't fix it.

          • How was GPS useless? GPS and maps are two different things. Don't you need both? GPS tells you your coordinates. A map tells you what to expect to find at those coordinates. A map can be printed, or electronic.
        • You still need to know how to read a sectional chart. But, many pilots will use an electronic one these days. ForeFlight mainly. If you are worried about battery life, it's an ideal use for an e-reader.
        • by jbengt ( 874751 )

          I'm old enough to remember when pilots carried large brief cases around full of maps and charts and the like.

          Those were still in use by major airlines 5 to 10 years ago. And the documents with maps, charts, checklists, and emergency procedures are still in use, they're just located in an electronic document reader, rather than in a flight bag full of 50 lbs of paper.

        • Re: Radio Beacons (Score:4, Interesting)

          by ceoyoyo ( 59147 ) on Friday January 26, 2024 @06:03PM (#64190978)

          Maps aren't the problem. Knowing where you are on the map is. Before radio aids to navigation pilots used dead reckoning, stars, visual landmarks, including rocks laid out on the ground in the shape of arrows.

          Celestial navigation has the notable problem that it doesn't work during the day. Visual navigation doesn't work when you can't see the ground or there are insufficient visible landmarks. Dead reckoning isn't very accurate.

          It's perfectly possible to use all three to navigate and both airliners and pilots are set up to do it, but they're not nearly as accurate as GPS. Accuracy is particularly important when you're near a war zone or hostile airspace. GPS was opened to civilian use in response to the Soviets shooting down Korean Air flight 007 after it strayed into their airspace.

          • The original meaning of IFR: I Follow Railroads.
          • Dead reckoning is probably fine assuming you don't plan to land in the war zone. You know your altitude, speed, and direction well, and your position is "somewhere over Ukraine" or whatever. Once you leave the war zone you figured out where you are and correct your course.

            • by ceoyoyo ( 59147 )

              You might want to google "Korean Air flight 007".

              Dead reckoning IS probably fine most of the time. The onboard inertial navigation systems are also fine virtually all of the time. Modern commercial air travel is hyper safe. The way it gets that way is not relying on "probably fine" but having backups for the backups, making sure that everyone who needs to be is aware when there might be a problem with one of the quadruply redundant systems, and making sure procedures allow for it. That's what this is.

        • And...what did they use to navigate before radio navigation?

          They'd use landmarks they could see on the ground.

          Early aircraft flew quite low, slow, and only in calm weather. Even then the flights were short, often mostly demonstration/stunt ("barnstormer") flights that would land on the same strip that they took off from. There were some mail carrying flights about this time that might get caught in some fog or something and get lost, such pilots could run out of fuel then land on an empty road or just crash. It was only when radio navigation was reliable that reg

          • Extending this - there are still big concrete markers scattered around the US, left over from when they were used as "trail markers" for airplanes - telling you where you were and which way to go to get to where you were going.

        • by PPH ( 736903 )

          And...what did they use to navigate before radio navigation?

          Ask Amelia Earhart.
          But seriously, radio navigation (following beacons with RDF equipment) has been around about as long as aviation. But that has been spoofable as well. Read Most Secret War [goodreads.com] and The Battle of the Beams [goodreads.com] for some interesting insight into how this was done during WW2.

      • The globe is full with beacons.
        However they are usually close to interesting points, and not necessary close to a random flight path.
        Modern beacons have a rotating antenna and they beam a digital signal indicating the direction the antenna is pointing at that moment. So if you are off by 10degree from your point of view, you get a 10, and so on.

    • One solution is passive systems such as optical navigation, which uses a down looking cameras and dead reckoning.
    • I clicked through to suggest invoking FCC clause AGM-88, and you beat me to it.

  • Well, one possibility would be to give airlines access to the US Military crypto in order to be able to use that channel as well...

    But given the age of the system, that would probably mean giving access to the Russians as well, because it's a single key even if we can change it. It's not like we can give a different key to every plane, and void it when they land.

    Maybe the newer European constellation can do that?

    But still, as said, not fast, so train the pilots to be able to use the old fashioned stuff.

    • Well, maybe not give them access to US Military GPS, and instead release an open encrypted international GPS system. I understand the work to pull that off would be enormous, but it would provide a jam free safe system.
      • A jam free system would require designing for that, and it would be very difficult to do. You're more likely to see a dedicated military system put up for that, while GPS goes pure civilian.

        At this point, we could probably replace GPS with something that is superior in all aspects except one: The installed base of civilian devices, which would all need to be updated at a minimum, but probably would have to be replaced.

    • by Guspaz ( 556486 )

      Does it actually matter if Russia gets access? The civilian and military signals at this point have the same accuracy, and Russia's already got their own equivalent satellite constellation, GLONASS.

      • by DarkOx ( 621550 )

        the civilian and military signals at this point have the same accuracy

        I am not aware of anything legal or technical the prevents the government from reducing the accuracy of the civilian signal again - if for example WWIII breaks out. They might not wish to do so as it would likely negatively impact things like automation and by extension the production of things we need, especially in war time; but i doubt we want to just give up the option to do so.

        GLONASS is more to the point however, and Russia is more than likely to make it available to our rival powers even if we did

      • Does it actually matter if Russia gets access? The civilian and military signals at this point have the same accuracy,

        Yes. Why would we want Russia to have capable GPS signals for it to use against Ukraine? It's already trying to block GPS signals so Western weapons which use GPS don't hit their target. If you can have a warhead land fifty feet away from the intended target, you've succeeded (dependent on the size of the warhead). It's the difference between having your people go [newsweek.com] splat [businessinsider.com] and being abl
        • by Guspaz ( 556486 )

          Russian weapons use the high-precision military signals from the Russian GLONASS constellation. How does access to GPS change that?

          • GLONASS is not quite as accurate. Also, the more different position data one gets, the higher the accuracy.

            • by Guspaz ( 556486 )

              Do we actually know how accurate GLONASS is? The only accuracy data we have is on the low-precision unencrypted signals. As far as I know, Russia hasn't released any information about the precision of the encrypted high-accuracy signals, but there's no reason to believe they're not similar to GPS, block II at least. There are also other global systems in operation that they can use, such as Galileo or BeiDou.

    • by FeelGood314 ( 2516288 ) on Friday January 26, 2024 @03:42PM (#64190462)
      All I need do is block the real signal and then play it back to you a millisecond late and you are confused by 300km. It doesn't matter if I can decode it.
      • It seems to me that if you block the true signal you're also blocking the fraudulent one, or you have complete control of the entire sky and GPS jamming is the least of your target's problems, and a replay attack without jamming the original signal is easily blocked.

        Have equipment that refuses signals that are too strong, and shield your antenna so it can't see the sky near the horizon, then add asymmetrical encryption to your signal and hand out the public key. Update the key as often as you like if you t

        • It seems to me that if you block the true signal you're also blocking the fraudulent one, or you have complete control of the entire sky and GPS jamming is the least of your target's problems

          The sky is a very big place. It's trivial to both be able to receive GPS signals perfectly while transmitting a signal that is able to overwhelm a target with false data. GPS signals are really really faint. You don't need a lot of power for this, just a highly directional antenna.

    • Wait ... You mean there is no public key authentication on GPS signals?
      That is insane.

      • GPS started in 1978. The encryption possible with it is relatively primitive compared to today. A complicating factor is that it needs to be unicast. It can still be done, in the sense that even if Russia gets the key they can't fake the authentication (easily), but the same key works for the entire system. If the key is compromised, you need to reissue to everybody as you rekey the satellites.

    • Old fashioned compass and sextant is not very accurate.
      • Old fashioned compass and sextant is not very accurate.

        How accurate is digital celestial navigation today?

        I recall that all the way back in the early days of the Cold War that the USA developed ICBM navigation that could do celestial navigation to get close enough for nuclear weapons. As the saying goes, close counts for horseshoes, hand grenades, and nuclear weapons. That was decades ago when this was developed, it's likely someone got much better at this now.

        My guess is that with the high definition cameras available today, and the high speed computers, tha

    • Well, one possibility would be to give airlines access to the US Military crypto in order to be able to use that channel as well...

      From what I remember precision codes can be effectively emulated by playing different GNSS systems running at different frequencies off each other to subtract the ionosphere. Perhaps if you are clever it would be enough detail for systems to be able to detect they are being fucked with because spoofing transmitters would never be able to get the timing/phasing right over a big enough area for it to be worth the effort.

  • by Anonymous Coward

    GPS signals come from what would colloquially be referred to as UP.

    Put your best tinfoil hat around the antenna... so that it only looks UP.

    Ignore the crap that comes from DOWN.

    Longer term...ideas...
    Before some clown decides to put their own GPS spoofing satellite in orbit... Phase array antenna. You have an idea where you are, you have a table that says were the satellites are, if the signal is coming from somewhere else in the sky, ignore the spurious signals.
    Put a highly accurate clock on the plane with

    • Maritime GPS antennas look more Up than others, to suppress multipath reflections over the sea. Consequently maritime antennas are now used in aircraft also.
    • by mosch ( 204 )

      I also wonder how much it would cost to have the flight deck track location based on gps _and_ location based on an inertial reference system; then perhaps warnings could be provided if those locations diverge, and the pilot could opt to use one, the other, or neither as appropriate.

      A super high-end inertial reference unit is in the hundreds of thousands of dollars, but I'd wager that something good enough to get you to the other side of a war-zone should be feasible for low five figures; maybe less if it c

    • Before some clown decides to put their own GPS spoofing satellite in orbit... Phase array antenna.

      Just how accurate do you believe phased array antennas can get? We are talking about satellites that are something like 13000 miles above our head, that leaves a lot of room for error in the angle to remove spoofed signals. (For those in countries that don't have a flag on the moon... 13000 miles is about 21000 kilometers.)

      Consider the area defined by wingtip to wingtip and nose to tail by an aircraft, that's the size of your phased array antenna. There's a limit on the angular accuracy of a phased array

      • by larwe ( 858929 )

        Also consider that those capable of reaching a high enough orbit to spoof a GPS satellite are not that far from just destroying satellites.

        A jammer doesn't need to be in orbit to be above you. Don't both the US and Russian ELINT planes carry active jamming/spoofing equipment as well as various snoopy receivers?

        • A jammer doesn't need to be in orbit to be above you.

          I agree but we are talking about spoofing GPS and counteracting this with phased array antennas on civil aviation aircraft. If the jammer is above a civil aviation jet aircraft then that could be something flying very high and fast, or at least very high. Getting above civil passenger jets is certainly possible but it would be expensive to maintain, therefore unlikely in the locations where it is being experienced.

          Thinking about this some more if the countermeasure is a phased array antenna on an aircraft

  • Its the only way to be sure.
  • Use all of them at the same time and do a "majority rule" positioning.

    Unless there is global war in multiple theatres, at least some of them will not be jammed

    • by DarkOx ( 621550 )

      More than likely all of them will be jammed if shit really hits the fan, or someone serious like the CIA decides they want bring an airliner down.

      Jamming weak satellite signals isnt all that hard. Spoofing them on the other hand, especially spoofing all of them reliably would be a lot more difficult to do with smallish low power package anyway.

    • by Fallon ( 33975 )

      Use all of them at the same time and do a "majority rule" positioning.

      Unless there is global war in multiple theatres, at least some of them will not be jammed

      You aren't talking about multiple theaters, theater just means one location. Jamming is occurring in one location. You can just spoof or jam signals for all the various GPS systems in one location.

      It doesn't matter if the ground stations for GPS are located in 1 location, Glonas in a different one & Galileo in a 3rd. They all have satellites overhead globally & the signals are in very nearby bands. You just have to blast out a jamming or spoofing signal in the target area & you affect all of the

  • Don't all big airliners already have triple redundant INS systems, augmented by GPS? And don't they give you a INS/GPS disagree warning when there is a difference in position? I know that INS can have 'drift' over time/distance and that it gets updated from GPS, but INS is the main driver, not GPS.
    • ... it gets updated from GPS, but INS is the main driver, not GPS.

      Thats the entire problem. Modern commercial avionics try to compensate for drift and unknowingly updating their "triple redundant main driver" INS with spoofed GPS positions, because the system is unaware the GPS location is not true. These flawed system designs is what IATA was unable to find a "fast tech solution" for.

      While attempting to bring improved precision and minimal training for commercial flights, these 'moderized' units introduced a total and fatal vulnerability to spoofing.

      • It's not the "entire" problem. INS updates from GPS because it has to update from something. You can't INS your way from New York to Paris.
        • Re: (Score:3, Informative)

          by Shag ( 3737 )

          It's not the "entire" problem. INS updates from GPS because it has to update from something. You can't INS your way from New York to Paris.

          Why not? "Doc" Draper INS'ed his way from Hanscom Field outside Boston to Los Angeles in a B-29 in 1953. With only one planned human course correction en route, the INS was only 10 miles off after a 2,600 mile trip. JFK-CDG is 40% longer, so you should be good to within 15 miles... you are using a 70-year-old INS, right? If you can't flat-out eyeball the airport at that distance, any kind of beacon the airport itself has should be pretty helpful.

          (Of course, Draper and his folks hadn't had time to test t

        • You used to be able to, before GPS was available.

          Flight 901 managed to navigate all the way from AKL into the side of Mt Erebus in 1979 by INS (oops somebody transposed some numbers when typing in the coordinates...)

        • by Ed_1024 ( 744566 )
          Actually, you can. Modern IRS are much more accurate than they are assumed to be by the aircraft systems. I have compared the actual IRS position after a transatlantic flight to the GPS position quite a few times and it is often less than a mile out. The type I fly initialises the IRS from GPS or manual position on the ground and does not update it during the flight. What it does do is have a separate working position which a blend of all the inputs: GPS, IRS, VOR/DME, LOC, etc. This is vulnerable to GPS ja
          • So it doesn't get thrown off by turbulence or something? Is setting the initial heading with enough precision much of an issue, since it's basically dead reckoning from there? Could commercial air travel at the scale, density, economy and safety we know it today be conducted just with inertial?
  • Pilots used to navigate with ground-based beacons (VOR, NDB), inertial references, and, sometimes, by simply looking out the window. Everybody is so in love with GPS (it is handy) that they've de-emphasized backup technologies.

    ...laura, private pilot who flies mostly by looking out the window

    • Many commercial airliners fly above the clouds and at night so they need alternative navigation systems. If there's a nearby war, presumably, not only GPS coordinates would be jammed/spoofed but pretty much any radio navigation. Probably best for commercial aviation to avoid conflict zones. I presume (but don't know) that the primary driver here is the Russia-Ukraine war making it very hard to fly over some Eastern NATO countries.

      The only thing I can think of is directional antennas such that one tru

      • by Shag ( 3737 )

        Even older technology, like celestial navigation, can be handy if you're above the clouds. Our aircraft go a little too fast for sextants nowadays, but plenty of military platforms, especially those that frequently operate above the clouds, like the SR-71 or B-2, have computerized celestial navigation systems that nudge their INS, and this has been the case for at least fifty years. Lots of satellites have star-trackers for position awareness too. I have no idea what the state-of-the-art is for aviation,

        • That seems like a good choice although perhaps a medium-term solution rather than a short-term one. You are right that one should be able to use celestial navigation from city-to-city and then visual navigation once one descends below the clouds.
  • This is collateral damage from an actual war, in which people are fighting for their lives.

    The difficulties in autonomous navigation that planes encounter is trivial by comparison.

    • It might be trivial by comparison but these types of spill-over effects can influence how people feel about wars and how countries react. So they shouldn't be trivialized in that sense.
  • by Casandro ( 751346 ) on Friday January 26, 2024 @05:42PM (#64190922)

    ... there are actually multiple way to spot simple spoofing.

    Essentially you put multiple GPS receivers on the extreme ends of your vehicle. If spoofing is done by a single transmitter, they will all get the same position, but different times. You can detect this. If spoofing is done by multiple transmitters, each one simulating a satellite, the distances between your GPS receivers will vary widely.

    So essentially you can either use timing-grade GPS receivers and compare their "PPS"-signal, or you can just take the position information from each GPS-receiver and, for example, calculate the distances of them. Those should, within error margins, never change. If there is a simple spoof, those distances will all be zero.

    Since aeroplanes often have wingsspans of 10 meters or more, the precision of the GPS position signal should be good enough to determine if it is "correct" or "zero".

    • The issue of identifying spoofing isn't the problem. The ICAO already allows the use of Galileo which is already used by modern planes and is able to detect spoofing as part of the system design itself. The issue is that once you know your signals are spoofed you still have a problem of navigating. The old ways weren't very accurate which is why satellite positioning is used in the first place. https://en.wikipedia.org/wiki/... [wikipedia.org]

  • IS only GPS being jammed ( IE only the US satellite navigation system) or is GPS being used Incorrectly to reffere t all satrelite navigation systems ( amongst them Galileo and beidu). Sorry for nit pucking pyr GOS is actually a trademark of the company that opperates the GOS constalation on beaif if the us, this is slashdot aftervall so one would expect such a basic thing to be correct but I'm not certain...
  • Would be possible to detect the signal direction and ignore anything that comes from ground? Maybe some kind of unidirectional antennas pointed to known satellite positions?
    Also, would GPS satellites digitally sign the signal? That'd be another way to certify the signal origin.

  • Why not add a digital signature to the true GPS signal? Since the signal includes time as well as position information, timestamps are automatically built in to prevent replay attacks. (The receiver would need to first fix on a true signal to set its internal clock, but this could be done before entering hostile territory.) The USSF (the organization that runs the GPS system) could publish public keys which could then be incorporated in receivers. Signals could still be jammed, but they could not be spoo
    • Why not add a digital signature to the true GPS signal? Since the signal includes time as well as position information, timestamps are automatically built in to prevent replay attacks.

      To alter location in GPS systems you don't need to replay or alter information all you need to do is alter the perceived signal flight times.

      • Which is precisely why I mention that the signals include time information, to prevent replay attacks.
        • Which is precisely why I mention that the signals include time information, to prevent replay attacks.

          All GPS receivers do is measure the time of flight of signals they receive. If a signal is delayed "time information" is not going to tell you what components of the measured flight time were a result of ionospheric conditions, increased path length, intentional spoofing or reflection.

          • All GPS receivers do is measure the time of flight of signals they receive.

            That's what current GPS receivers do. I'm suggesting that those in mission critical applications have anti-spoofing checks built in. They would look for synchronization errors between their internal clock (which would be set when synced on a true signal, as I mentioned) and those coming from the GPS signal. If someone attempted to replay a true signal at a later time, they clocks would not sync up and the unit would know the signal was spoofed. Digital signatures could prevent altering the time or spati

            • That's what current GPS receivers do.

              If you are not measuring time of flight to judge location what do you intend on measuring in its place?

              I'm suggesting that those in mission critical applications have anti-spoofing checks built in. They would look for synchronization errors between their internal clock (which would be set when synced on a true signal, as I mentioned) and those coming from the GPS signal. If someone attempted to replay a true signal at a later time, they clocks would not sync up and the unit would know the signal was spoofed. Digital signatures could prevent altering the time or spatial data to fool receivers.

              The problem is not that someone records a bunch of GPS signals and plays them back later at their convince. It's that the signals are actively repeated in real time with subtle delay that emulates an effective difference in the path length between the receiver and satellites in the constellation causing a receiver to think it is somewhere else. While signatures make spoofing more difficult they fundamenta

  • If people could do it for missiles and shit with 70s era tech it has got to be possible to load something like SRTM into a database and find your location by matching terrain and combining it with compass, inertial...etc.

  • Cynical me thinks that there are existing technical solutions, but the airline industry ignores them because it will "cost too much."

    Case in point: the Boeing 737 Max 9 door plug blowout. The root cause is clearly a failed safety culture brought about by "saving money" on "expenses" that don't "contribute to the bottom line".

    Just like the 737, until there is a massive failure that can even cause a CEO to get kicked out and the stock to take a real nose dive (pun intended), they will do absolutely nothing

  • War makes for great innovation. It's awesome to see and can make for a bright future. Assuming we make it past the bleak parts.
  • GPS isn't the only GNSS in town. Are the spoofers spoofing ALL of them? If not, why don't aircraft rely on a majority vote of the different GNSS system readouts?

    My phone gets data from all of them - probably yours does too. How hard is this?

    • by gweihir ( 88907 )

      Since this is non-native spoofing, yes, the attackers will be spoofing all of them. Obviously only the network controllers can natively "spoof" their own network, i.e. send incorrect signals from the satellites themselves.

  • This has been solved already, use a 5 sensor combination with multiple redundant systems.

    1. GPS
    2. VOR
    3. Inertial
    4. Celestial
    5. Image recognition of observable landmasses

    • I’ll bite and take you seriously.

      1 through 3 are plausible. 4 only works in good weather, so..no. Number 5 is sorta plausible except most civilian jets dont carry terrain mapping radar (I think).

      Bottom line is, yes, a solution is plausible. But not something that can be installed on planes next month.
  • If it's possible to navigate on the Moon with AI and visual signs, why it's not possible to fuse even more signals to compensate for the loss of GPS? There surely are technologies to see through clouds and then technologies to recognize landscape or even stars above.
    • This Moon AI visual landmark recognition technology is fairly new and in 100% of the cases so far the spacecraft landed upside down. Pilots don't like to be in that situation.
  • So... update the GPS communications protocol to require authentication against a trusted public key? (Either that, or switch in the CRM-114 radio frequency discriminator to reject all transmissions not preceded by the correct three-letter code prefix.)
  • The problem is GPS is like http: lacking encryption and non repudiation/ 1. As many modules do today: use multiple GNSSes to reject any single spoofed constellation. It is extremely unlikely that all constellations will be spoofed because they are sufficiently unique in detail. 2. Have the human in the loop to not rely completely on electronic positioning, and InS whwre possible. 3. Reject impossible position changes in the GNSS module. 4. All constellations should migrate to public keyed receivers that are
  • I know GPS is old, but shouldn't it be possible to have GPS send its timestamps signed with a private key, so receivers can validate it actually came from the satellites?

    That would allow to detect and avoid spoofing, but would still allow the US military to do whatever they want with the signal.

Think of it! With VLSI we can pack 100 ENIACs in 1 sq. cm.!

Working...