Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
Government Security Transportation

Schneier Has Something Good To Say About Airport Security 226

Posted by timothy
from the this-will-disrupt-the-lax-theft-model dept.
Bruce Schneier points out on his blog a proposal to use electronic randomizers at airport security checkpoints. Schneier writes there: "I've seen something like this at customs in, I think, India. Every passenger walks up to a kiosk and presses a button. If the green light turns on, he walks through. If the red light turns on, his bags get searched. Presumably the customs officials can set the search percentage. Automatic randomized screening is a good idea. It's free from bias or profiling. It can't be gamed. These both make it more secure. Note that this is just an RFI from the TSA. An actual program might be years away, and it might not be implemented well. But it's certainly a start." In this case, the proposal is for randomizers that direct passengers to particular conveyor-belt lines for screening.
This discussion has been archived. No new comments can be posted.

Schneier Has Something Good To Say About Airport Security

Comments Filter:
  • Same in Mexico. (Score:5, Informative)

    by icebike (68054) on Friday July 19, 2013 @06:55PM (#44333801)

    Nothing new here.
    Had the same experience in mexico a dozen years ago.
    Red light or green light.
    But back then, there was a guy standing on a switch could just flex his knee to make additional selections if you looks particularly shady.

    • by jcr (53032)

      Yeah, went there a short while ago and the Mexican customs officer asked me to put my bag through an x-ray machine, then push a button. Got a green light, so they waved me through. Not sure how many people got the red light, but our whole flight got through customs pretty quick.

      -jcr

      • Re:Same in Mexico. (Score:4, Informative)

        by realityimpaired (1668397) on Friday July 19, 2013 @09:57PM (#44334705)

        Most of the world is pretty civilized about customs... it's really only the US, and a couple of airports in Canada and large airports in Europe that are gestapo-land.

        I've seen tighter security at Dayton, Ohio than I did last time I flew into Charles de Gaulle: on arrival in Paris, we formed a lineup for customs, and a guard came out and shouted to the line "anybody with a Canadian passport, line up here", and those of us with Canadian passports didn't have to pass a security check at all, they just asked if we wanted the CDG stamp on the passport and waved us through. And that was post-9/11. On the way back, it was pretty much the same... put your bag through the x-ray machine, go through a metal detector, and they let you on the plane. I'm guessing that they'd already done the security/background checks, since you need to give your passport number when you buy the plane ticket these days, but it could just be that Air France is more civilized about things like that.

        Still... by far the most relaxed security I've ever seen in an airport was in Willemstad, Curacao. The plane landed at 4am, which probably had something to do with it, but it was basically a case of "welcome to the island, enjoy your stay!" for everybody.

        • Willemstad (Score:4, Insightful)

          by dutchwhizzman (817898) on Saturday July 20, 2013 @03:40AM (#44335749)

          Passengers on flights coming from Willemstad into Amsterdam get checked 100%, because of the lax checks at Willemstad and the proportionally high amount of drug trafficking on this route.

          Doing random checks on people not selected because they trigger certain alerts that make them suspicious makes it hard for customs/safety to get bribed and increases the chance the bad guys get caught. Once the bad guys figure out how not to stand out or bribe the guards, it's hard to catch them otherwise. This is why the random selector is better than having people do the random part of the selection. You want to check the poor African guy travelling alone to a rich country with a stop of one day in central America, because that's suspicious. But that doesn't mean that the mom and pop with a kid coming back from a 2 week holiday in Mexico can't be smuggling in a few Ks of cocaine as well. Having them press the button will make them think twice about the risk and it will probably even have a preventative effect in itself.

          • Passengers on flights coming from Willemstad into Amsterdam get checked 100%, because of the lax checks at Willemstad and the proportionally high amount of drug trafficking on this route.

            Could do. I've never flown from Willemstad to Amsterdam, just Willemstad to Toronto. Actually, I've never flown to Amsterdam period... the handful of times I've been there (I have family in Delft), it's been arrival by train after flying into CDG. I could fly direct from here to Heathrow or Amsterdam directly, but it's like 3x the cost of driving to Montreal and flying into CDG. Even after you factor in a couple of weeks of airport parking, it's still cheaper to fly to France and take the train. :(

            It doesn'

    • Re:Same in Brazil. (Score:3, Interesting)

      by dafradu (868234)

      Nothing new here.
      Had the same experience in mexico a dozen years ago.
      Red light or green light.
      But back then, there was a guy standing on a switch could just flex his knee to make additional selections if you looks particularly shady.

      We had (still have?) this in Brazil. But i think it was only in the customs area, not really for security screening.

    • by emag (4640)

      Yeah, our trip to Cancun a few years ago, we got a red light on the way in through customs. They're surprisingly efficient at the search, probably because they don't want to piss off the tourists.

      • Also, I imagine there's not a huge demand for smuggling goods into Mexico.
      • Re:Same in Mexico. (Score:4, Interesting)

        by pipatron (966506) <pipatron@gmail.com> on Saturday July 20, 2013 @07:26AM (#44336253) Homepage

        The speed may also have to do with the fact that it's supposed to be random - They have no reason to believe you're some smuggler just because the random selector picked you out. You're most likely just some tourist.

        Had the selection been on who looks the most suspicious in the eyes of some middle-manager customs officer, the staff better find some drugs or they will have proven their boss wrong, so it'll take a lot longer to search your bags.

    • by cusco (717999)
      They've been doing this in the airport in Lima, Peru, for at least 24 years.
    • by Joce640k (829181)

      But back then, there was a guy standing on a switch could just flex his knee to make additional selections if you looks particularly shady.

      Yep. You just know they'll game the system if it's ever implemented here.

      It could be done fairly with dice, picking balls out of a hat or something physical like that, but it won't be. The thought of not being in control freaks them out.

    • by Simulant (528590)
      Yes Mexico has been doing this since at least the early 90s.
  • Surely (Score:2, Funny)

    by Anonymous Coward

    Yes but if it's random surely they would need a separate belt for the foreign looking people thats more random.. Right?

  • by edjs (1043612) on Friday July 19, 2013 @07:00PM (#44333845)

    Issue the TSA some dice?

    • by d'baba (1134261) on Friday July 19, 2013 @07:17PM (#44333969)

      Issue the TSA some dice?

      Only if I can negate the search with a saving throw...

      • by Darinbob (1142669)

        "Ok, let's see. Your base THACO is 10, with -1 for having small suitcase, and another -1 for TSA as racial enemy, however +1 because of the tiny plume of smoke coming from your shoes, so roll a 9 or better."

        • -1 for TSA as racial enemy

          This is a diplomacy check, not combat. Realistically, being the TSA's racial enemy should raise the difficulty, not lower it - just like in real life.

  • by cosm (1072588) <thecosm3 AT gmail DOT com> on Friday July 19, 2013 @07:00PM (#44333847)
    I propose a device for random selection, consisting of a circular round object minted by our very own Federal Government that generates binary decisions with 50% probability, I can deliver these devices to the TSA at 100 units a shipment for a small price of $340,000 per shipment. I can have them delivered to every airport in the country within 2 weeks and we can implement this program by the Fall. They require no maintenance other than a 10 year service contract that adjust their randomness factor every year.

    Any VC's out there?
  • by Anonymous Coward on Friday July 19, 2013 @07:04PM (#44333885)

    Is there evidence that profiling passengers based on appearance and behavior is not more effective than randomized screening?

    • by Mitreya (579078)

      Is there evidence that profiling passengers based on appearance and behavior is not more effective than randomized screening?

      I would assume profiling passengers based on behavior would work. Alas, that requires workers with some real behavioral training and too few contractors would benefit from that (so we buy $250K useless scanning machines instead).

      Not sure what the is the point of randomized screening? Keeping us 10% safe? Keeping terrorists 10% concerned?

      • by Anonymous Coward on Friday July 19, 2013 @07:39PM (#44334139)

        I don't want to misrepresent Schneier's position, but I've read articles of his in the past which basically say a profile is bad because it gives a way to avoid screening: avoid matching the profile.

        Randomized screening may allow a single terrorist through, but something like 9/11 which required 19 guys means almost certainly one of them will be caught. If one is caught, you know to look for others.

        Of course, the real solution is locking the cockpit doors and passengers who will kill anyone who tries to hijack an airplane.

        • More importantly, I guarantee that were such a system to be used in the US, it would include an override that watching agent could trigger a red light if he saw something suspicious... if only to ensure the continued employment of said agents. And such an override would result in profiling, negating one of the major advantages of the system.

           

          • by Dahamma (304068)

            it would include an override that watching agent could trigger a red light if he saw something suspicious... if only to ensure the continued employment of said agents. And such an override would result in profiling, negating one of the major advantages of the system

            Wait, *how* is not allowing an agent who saw something suspicious to stop someone an *advantage*!?

            "Sir, I just saw this guy typing a text message 'almost through - they'll never find it before I get on' - should I stop him?"
            "No, that would be profiling. Just make sure he pushes the button."

            • Profiling gives criminals a way to game the system; if you don't look like the profile then you don't get tagged as a potential criminal (it also allows some unfortunate biases to come into play by the profiler). The solution, Schneier suggests, is a system that by its simple randomness, does not allow profiling or gaming.

              Whether you agree with his logic or not, I strongly doubt that any such system would be allowed into common usage in US airports without an override. This negates the very advantages Schneier advocates. Whether this addition strengthens the overall system is up to debate (Schneier would argue that it does not), but the addition of a human override weakens those aspects that Schneier looks upon favorably.

              Myself, I think all such methods are extreme overkill and that its far more likely that criminals interested in damaging the US with such attacks will strike at our practically undefended infrastructure, be it the huge AV fuel tanks at the airport, or any of the bridges or tunnels in a major city, or some toxic chemical depot in an urban area. Most of these are protected by little more than rusty chain-link fencing and an underpaid security guard and could cause far more harm than a simple plane crash. It's these weaknesses that terrify me far more than the presumed risk of some schmuck with a razor blade hijacking a plane. I'd rather they stop wasting money frisking passengers for penknives and spend it shoring up those vulnerabilities instead.

              Or alternately, we could stop pissing off three-quarters of the world so they all don't want to blow us up. It's just whacky enough an idea to work!

              • by thegarbz (1787294)

                Except that not looking like the profile is more difficult if you are profiled by race, passport origin, and social manner.

                Sure the occasional terrorist has been white, blond, and otherwise as different from the typical profile than it comes, but the vast majority of terrorist have been of one ethnicity.

                By profiling you improve your hit rate over true random sampling at the expense of letting some targets slip through.

        • by Dahamma (304068)

          Randomized screening may allow a single terrorist through, but something like 9/11 which required 19 guys means almost certainly one of them will be caught. If one is caught, you know to look for others.

          It wouldn't have made a bit of difference, since nothing they did was illegal at the time. They were basically using a few (at the time allowed) X-Actos in their luggage and several months of training on how to fly the planes.

          You assume the terrorists are all stupid enough to try to bring something *currently* illegal through screening, which will almost never be the case.

        • Randomized screening may allow a single terrorist through, but something like 9/11 which required 19 guys means almost certainly one of them will be caught. If one is caught, you know to look for others.

          Orthogonal point:
          Except for the fact that the worst thing they had on them were boxcutters. Nowadays they'd just confiscate them and let you board anyway, they wouldn't even notice that 19 guys across 3 planes had tried to board with boxcutters.

          So 50% get through with boxcutters (75% if they only screen 1 out of 4) versus 100% getting through if they can arrange to avoid fitting the profile. Either way the danger is essentially the same.

    • by retchdog (1319261)

      since there aren't that many actual terrorists to test the system with, there really isn't much evidence... but there is some standard wisdom.

      appearance: yes, because the adversary can easily figure it out and plan around it, or at least this is the usual argument. also, any judgment call or decision branch in the line slows it down for everyone because people are stupid and stubborn.

      behavior: this might be effective, but it would slow the line down significantly and/or cost a lot. the point of security the

    • Pretending that anyone from an 80-year old grandmother to a four year old presents an equal probability of trouble...

      Takes a lot of acting chops to claim that's a good idea with a straight face.

      • by taustin (171655) on Friday July 19, 2013 @08:24PM (#44334319) Homepage Journal

        The oldest suicide bomber [inminds.com] I can find was a 64 year old woman. And an youngest [mirror.co.uk] person arrested for trying to be one is 11.

        Not quite your 4 to 80 range, but close enough that you look pretty silly and uninformed.

        • And it makes you look illiterate. What the GP actually said was:

          80-year old grandmother to a four year old presents an equal probability of trouble

          Pointing out that there is an extreme end to the age scale of terrorists doesn't demonstrate that people at those extremes have an equal probability of being a terrorist. The 64 year old woman, and the 11 year old kid - are they a representative sample, or a statistical outlier? Because if they're outliers, you've just proved the GPs point for him.

      • by cffrost (885375)

        Pretending that anyone from an 80-year old grandmother to a four year old presents an equal probability of trouble...

        A grandmother would be an excellent candidate for recruiting to carry a proxy bomb. [wikipedia.org] TSA drone SuperKendall would likely wave her right through.

        Takes a lot of acting chops to claim that's a good idea with a straight face.

        I'm confident that that grandmother will come up with whatever "acting chops" are necessary to get that package through in order to spare the life of her kidnapped grandchild.

        Note: Despite this post, I am not a supporter of TSA's draconian "security" practices, which I consider to be in violation of our rights under the Fourth Amendment. I stopped flying seven years

      • "Probability"? Your claim is based on a model of reality where all airline passengers roll percentage dice to determine if they are terrorists. 80-year-old white grandmother - probability A. 20-year-old minority male - probability B.

        - Any non-random selection algorithm is a known algorithm. This is obvious, because if the TSA is going to profile, they're going to profile the same way you would, and for the same reason.
        - That means a terrorist group knows an older white person is going to pass where a younge

    • by taustin (171655) on Friday July 19, 2013 @08:20PM (#44334297) Homepage Journal

      Profiling inevitably produces more false (usually an order of magnitude more) positives than real positives, and generally produces as many false negatives as false positivves. In other words, you're a lot more likely to spend your time searching someone for no reason than catch an actual bad guy, and as likely to let a real bad guy through as not.

      And that assumes the profiling is done in an objective, unbiased manner. When human decisions are made as to who gets profiled, there will be bias, whether the humans doing it realize it or not. This, at least, eliminates that.

      I'll bet, though, without reading TFA, that there is no thought whatsoever of this replacing any current profile based screening, only being used in addition to everything done now.

      • by brit74 (831798)
        Yeah, but is that better or worse than random selection? Random selection is going to produce a ton of false positives and a lot of false negatives.

        In other words: if they randomly select 10% of the passengers and 1 out of 1,000 is a terrorist or drug mule, it means that 90% of all "bad guys" will get through without a problem (90% false negative rate), and it means that virtually everyone (999 out of every 1000 people) who gets searched will be innocent (99.9% false positive rate).

        If people can pick
    • by cheekyjohnson (1873388) on Friday July 19, 2013 @08:41PM (#44334383)

      Frankly, I don't care how effective either is; just get rid of the TSA and stop harassing people, even if at random or by profiling.

    • by cffrost (885375) on Friday July 19, 2013 @08:51PM (#44334417) Homepage

      Is there evidence that profiling passengers based on appearance and behavior is not more effective than randomized screening?

      Yes. MIT published a paper entitled "Carnival Booth" that demonstrated that random screening is more secure than profiling, essentially due to the latter's vulnerability to probing:

      Carnival Booth: An Algorithm for Defeating the Computer-Assisted Passenger Screening System [mit.edu]

      A Lay Explanation of the MIT Research Paper [Carnival Booth] [boycottdelta.org]

      Schneier on Security: Profiling [schneier.com]

      Proxy bombs [wikipedia.org] are also difficult to screen for with profiles.

    • by brit74 (831798)
      I recently listened to a Scientific American podcast where they did some "lab" tests to figure out whether or not someone was carrying a contraban package. They had five people walk through a room. One of the five had a contraban package. Random selection would produce a 20% rate of success. I believe they had a "hit" ratio of 30% using ordinary college students - which is slightly higher than random. (They also did a test with college students who tested high on the "psychopath test" and they were actually
      • by 0111 1110 (518466)

        But in the real world one or more decoys would probably be used. Just plan it so that several nervous, sketchy looking muslims with long beards enter security before the lily white, clean-cut guy wearing a suit and tie and carrying a laptop and acting just like the vast majority of business travelers.

  • They give you a piece of paper with a block dot on it.

  • by KPexEA (1030982) on Friday July 19, 2013 @07:10PM (#44333925)
    You stand on a mat and it directs you to one of three different security lines, presumably to randomize the screeners incase you have one on your payroll.,
    • by Mitreya (579078)

      You stand on a mat and it directs you to one of three different security lines, presumably to randomize the screeners incase you have one on your payroll.

      Is there any evidence evidence that someone is trying to get through? (not to mention to recruit a screener)

      Have they ever caught anyone?

  • by TechyImmigrant (175943) on Friday July 19, 2013 @07:16PM (#44333965) Journal

    Any terrorist with a simple grasp of binomial theory could work out the number of terrorists to send through the gate necessary to achieve a 90% confidence that one of them gets through with the bomb, given only the relative probability of red vs. green.

    So we must prevent binomial theory getting in the hands of terrorists.

    • E.G, with a 90% chance of getting a red, the terrorist mastermind would need to send 7 terrorists through to get a 52% chance of one of them getting through unsearched.

    • Re:Binomial Theory (Score:4, Insightful)

      by Anonymous Coward on Friday July 19, 2013 @07:26PM (#44334045)

      Any terrorist with a simple grasp of binomial theory could work out the number of terrorists to send through the gate necessary to achieve a 90% confidence that one of them gets through with the bomb, given only the relative probability of red vs. green.

      Any terrorist can realize that a security line (which gets huge during busy season) is as good of a place as any to detonate a bomb. No security _before_ the checkpoint.

      • by mysidia (191772)

        Any terrorist can realize that a security line (which gets huge during busy season) is as good of a place as any to detonate a bomb. No security _before_ the checkpoint.

        Protecting you while you're waiting to enter the secure area is not their job --- their job is to prevent weapons from coming onboard, or people getting into the security area with contraband.

      • http://en.wikipedia.org/wiki/Category:Terrorist_attacks_on_airports

        There is a whole list and the most recent one was in Russia I believe.

        But there is a problem, Dirty Harry justice. We don't mind how many people the criminal in a Dirty Harry story kills, just as long as they are blown away at the end. What hurts about 9/11 is that they got away with it. Had they been gunned down in a fight with the NYPD, they would have been considered losers.

        You could taste some of that with the Russian school/theather

    • Re:Binomial Theory (Score:4, Insightful)

      by rolfwind (528248) on Friday July 19, 2013 @07:28PM (#44334071)

      Assuming they would put the airport on lockdown and start searching everyone if they found one person with a bomb, sending more people through would just increase the chances of getting caught and foiled.

    • by taustin (171655)

      If the plane takes off anyway after finding a hijacker/bomber trying to get on, the first time, it won't after that until every single passenger has been stripped searched.

      Duh.

  • A little wire underneath, or even a radio receiver. Push the button... red light!

    It only "can't be gamed" if you have independent sources checking them out to make sure they're MADE not to be gamed, and that they stay that way AFTER manufacture.

    This is the same fundamental problem they had with electronic voting booths. They couldn't be "gamed", either. But they were.
  • If hands are cold -> passenger must be nervous -> must have something to hide -> red light.
  • I saw this when I went to Mexico back in February. I wouldn't mind this at all. I'm not shocked at all it only took 12 years for the TSA to get out an RFI on a really fucking simple concept, one that isn't too difficult to implement.

    I don't really see them implementing it well, but that's another story. Small steps

  • by hawguy (1600213)

    From the summary it sounded like this would randomly choose which passengers get picked for extra screening. That makes sense and I can see why this would be helpful in ensuring that random screenings really are random.

    However, the in the TSA's proposal, it sounds more like they want a device that chooses which line you go to for the normal screening. So rather than passengers (or a TSA agent) automatically balancing themselves across the lines, if several neophyte fliers end up in one line and cause a b

  • Except (Score:2, Insightful)

    by phantomfive (622387)
    Except it won't keep people from being groped. That will be the end of the TSA, once enough people have been groped, they will oppose it.
    • Re:Except (Score:4, Informative)

      by phantomfive (622387) on Friday July 19, 2013 @08:09PM (#44334267) Journal
      I got modded down for some reason, but wow, the first time you get groped at the airport, it all changes from abstract theory to miserable reality. To feel the soft caresses of the male security guard as he brushes by your balls......

      That is something that affects you.
  • In Mexico it's long been like that. But I think this makes Mr. Schneier a bit gullible — It is quite common to find experiences of people who are clearly "fast-tracked" into revision. Yes, I have had red lights several times, and it has some correlation with my age and looks at the time.

  • I think he's mistaken. There are two "channels" when you pass through customs. Red channels if you have something to declare. Green channel if you have nothing to declare. If you go through the red channel, you have to declare the good you are bringing into the country. Going through the green channel isn't a free pass. You could still get your bags inspected.
    • by u38cg (607297)
      I'm pretty sure Schneier knows the difference between security screening and customs clearance.
  • by the_rajah (749499) * on Friday July 19, 2013 @07:51PM (#44334213) Homepage
    I worked for T.I. when they were making LED watches in the Dallas plant. Security asked me to design a random search generator hooked to a switch on a turnstile leaving the assembly area. They could select the search frequency by means of a DIP switch.
  • by FuzzNugget (2840687) on Friday July 19, 2013 @08:10PM (#44334269)

    My guess is that this creates a psychological game of chance that a would-be attacker might not risk; and perhaps searches are more thorough when personnel isn't having to rifle through *everyone's* stuff.

    There are two things we know have strengthened security:

    1) reenforced cockpit doors
    2) passengers who know the deal and won't put up with any shit

    We could make further *real* changes to improve security, like having highly trained and skilled air marshalls on every flight, hiring actual officers with actual skills to patrol airports instead of hiring glorified assembly line monkeys, searching bags strategically based on behavior and questioning ... but those things are just too expensive in the "wrong" way (ie.: they don't line the coffers of porno-scan manufacturers and the bureaucrats who do then favors; it would kill the job creation program for unskilled, slack-jawed mouth breathers)

  • ...is that it's an anti-corruption mechanism. It's really hard to bribe the computer.
  • How do we know whats behind the button? It's easy enough to claim that its simply a RNG, but it could equally be radio controlled by a guy watching one of the camera feeds. This is akin to closed source encryption software - we gotta trust that the guys who built it are truthful. Sorry Bruce, this is actually security theatre.

  • I am sick of this "we cannot profile" crap. The israelis profile based on "behaviour" as their main focus. I don't care how "trained" a terrorist is, they will always have a "tell" and they will always be nervous. Stop irradiating people and stop with this random violation of human rights in the name of political correctness. I am sorry but I am not interested in playing russian roulette with my life. That is exactly what this is because it is based on the premise that they can randomly find the terrorist.
    • by j-beda (85386)

      I am sick of this "we cannot profile" crap. The israelis profile based on "behaviour" as their main focus. I don't care how "trained" a terrorist is, they will always have a "tell" and they will always be nervous. Stop irradiating people and stop with this random violation of human rights in the name of political correctness. I am sorry but I am not interested in playing russian roulette with my life. That is exactly what this is because it is based on the premise that they can randomly find the terrorist.

      Enough is enough. We have to start profiling based on behaviour and background checks and allow law abiding citizens and visitors to travel relatively unmolested. If we continue not profiling then the terrorists have won. Find and prosecute the terrorists and attempted terrorists and leave people who want to visit peacefully and spend money in your countries alone.

      Doing evidence based profiling would probably be a good idea, but it is difficult, and to do it well would require a level of background checking and data mining that I think many would be uncomfortable with. Heck, even determining with high confidence just the identity of the 300 people to board the plane is a non-trivial task. Having a purely random component to determining who gets increased scrutiny is a very good way of dealing with the limitations of our screening resources.

      From a game-theory perspect

  • Presumably the customs officials can set the search percentage.

    When can they set the percentage?
    *man speaking Arabic walks up to the device* *operator quickly sets percentage to 100%*

  • "It can't be gamed"

    OK, I repeat so you can reflect on it: "It can't be gamed"

    Oh, did I tell you It can't be gamed?
  • I don't know if they still do it with all the nude scanners but the old metal detectors would randomly decide if you get subjected to secondary search by flashing a different light when you go through

Real Users find the one combination of bizarre input values that shuts down the system for days.

Working...