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TSA Paid $1.4 Million For Randomizer App That Chooses Left Or Right (geek.com)

An anonymous reader writes: For those of you who have traveled through U.S. airports in recent years, you may have noticed the Transport Security Administration (TSA) use a Randomizer app to randomly search travelers in the Pre-Check lane. The app randomly chooses whether travelers go left or right in the Pre-Check lane so they can't predict which lane each person is assigned to and can't figure out how to avoid the random checks. Developer Kevin Burke submitted a Freedom of Information Act request asking for details about the app. The documents he received reveals the TSA purchased the Randomizer iPad app for $336,413.59. That's $336,413.59 for an app, which is incredibly simple to make as most programming languages of choice have a randomizing function available to use. What may be even more intriguing is that the contract for the TSA Randomizer app was won by IBM. The total amount paid for the project is actually $1.4 million, but the cost is not broken down in Burke's documents. It's possible IBM supplied all the iPads and training in addition to the app itself.

53 of 334 comments (clear)

  1. Panama Papers by Anonymous Coward · · Score: 5, Funny

    TSA soon to be appearing in the Panama Papers...

  2. That breaks down to... by Anonymous Coward · · Score: 5, Funny

    $413 dollars in developer time to create the app and $336,000.59 in corporate overhead and bloat, the additional $1,000,000 is just for Evil

  3. Standard C library... by Etherwalk · · Score: 2, Insightful

    The question is whether it is truly random or not. If they spent $1.4M and got a truly random result, fine. It's absurdly pricey, but it works. If they spend $1.4M and got the rand() function, then terrorists might be able to exploit it to escape random searches.

    1. Re:Standard C library... by rwven · · Score: 5, Insightful

      That's really stretching things. If you use something as simple as microseconds on a clock as the seed for your "random" number generation, there's "pretty much" no way you can exploit that short of hacking the device itself. It's not like people are going to stand there with a stopwatch and tell the TSA guy "OK....press the button...Now!"

    2. Re:Standard C library... by Anonymous Coward · · Score: 2, Informative

      Well, you don't even need a cryptographically secure random number. You just need one that can't be predicted by anyone on that day, which isn't really a tall order. You could do it in any language of your choice, let everyone see the code, and seed the generator with the current time in seconds (or ms or whatever). Still nobody would be able to guess, because they can't predict when you're gonna press that button.

    3. Re: Standard C library... by amRadioHed · · Score: 2

      Good luck studying that for weeks when the seed is different for every device and probably resets daily.

      --
      We hope your rules and wisdom choke you / Now we are one in everlasting peace
    4. Re:Standard C library... by Anonymous Coward · · Score: 5, Interesting

      If you use something as simple as microseconds on a clock as the seed for your "random" number generation, there's "pretty much" no way you can exploit that short of hacking the device itself.

      You would be surprised in just how many ways random numbers can be screwed up.

      First "simple as microseconds on a clock" is good, I have seen quite a bit of "randomized" code seeded with the system time. 15 milisecond resolution is the normal case and often leads to duplicated random sequences. High resolution timers exist and are widely available today, however they have to be actually used to help. Alternatively why use a random number generator if you could just request the microsecond time for each request - the low bits should be rather random.

      Second mapping the range of the random number generator to your target range without killing the distribution is often non trivial. C++11 came with a whole library to replace rand() and several presentations on the topic, including how rand() % 2 isn't a 50:50 split when the original range has an uneven amount of values.

      Third you often don't want a random selection - a fully random sequence can contain long stretches of only left or only right, which can overburden the affected lane while the other remains empty. Which means you somehow have to enforce the wanted distribution over shorter sequences. A simple solution can be implemented by shuffling a list with the wanted ratio of left/right values and a reshuffle each time the list is used up, games sometimes use this to avoid long loose streaks and prevent long win streaks.

    5. Re:Standard C library... by gweihir · · Score: 2

      There is absolutely no need for "true" random (whatever that is, the physical processes called "true random" are actually "we have no clue how it works, but we have a statistical model"). CPRNGs (Cryptographic Pseudo Random Number Generators) are entirely fine for this, because they are not predictable, unless you have the full state. Nobody needs "random" for this application here, non-predictable is entirely fine. As to seeding, a few precisely timed button-presses on start, a seed file from the day before and just timing whenever a new decision is asked for gives you a good initialization without problem.

      This is a _solved_ problem.

      --
      Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
    6. Re: Standard C library... by Lumpy · · Score: 2

      reset the seed hourly based on user input like keys and mouse movement. 100% hackerproof unless the machine is compromised.

      --
      Do not look at laser with remaining good eye.
    7. Re:Standard C library... by Jason+Levine · · Score: 4, Insightful

      That cartoon villain level of planning isn't needed at all. There are gaping holes in the TSA security net. They take the "security" out of "security theater"

      Not to mention the huge security hole before you hit the TSA checkpoint. Especially if you are in a large airport during a busy time of the year.

      TSA: "We spent $14 million to make our security process safer and more effective!"
      Terrorists: "That's nice. We think we'll detonate our bombs in this nice, crowded security line. Not only will we kill a lot of people, but then you'll shut down this airport for days wrecking even more havoc on people's travel plans."

      --
      My sci-fi novel, Ghost Thief, is now available from Amazon.com.
    8. Re:Standard C library... by vlad30 · · Score: 4, Insightful

      Terrorists: "That's nice. We think we'll detonate our bombs in this nice, crowded security line. Not only will we kill a lot of people, but then you'll shut down this airport for days wrecking even more havoc on people's travel plans."

      Always wondered why terrorist chose airports why not a church/synagogue packed with people on a Sunday/Saturday and zero security its easy pickings, then it would be Christians and truly a religious war but they attack airports sporting events concerts, symbols of western affluence. sort of answered my own question its not really about religion is it.

      --
      Your'e all thinking it, I just said it for you
    9. Re:Standard C library... by Anubis+IV · · Score: 2

      A) If IBM discovered a way to make something that is truly random, then $1.4M is not only a bargain, it's revolutionary.

      B) IBM didn't make something truly random. They used a psuedo-random number generator (PRNG), the same as the rest of us, and we already have ones that are good enough for advanced cryptography. For a left/right decision, you could seed it with something trivial like the time of day accurate to the ms and have a degree of randomness sufficient to thwart attempts at exploiting the randomness of the decision.

      C) The decision itself is flawed in its conception, since you only need to have a few terrorists lined up consecutively to have a high degree of certainty of having one or more go through the line you want.

    10. Re:Standard C library... by KGIII · · Score: 2

      A couple of things to add to the above...

      While it's a philosophical matter, I do not know if we even have true random. We have unpredictable pretty well covered and we have some things (like radioactive decay) that aren't yet understood well enough to be predicted. There are suitable sources for unpredictable results but I'm not really sure that we've got true random. I think that, in the few areas where we do have something close, that it's actually a lack of understanding on our part that makes us think that it is random.

      Then, they don't want random - not in the sense that lots of people seem to think. If everyone were randomly selected then a near 50% would go through the line to get the extra searching. They don't want that - they might want something like 1:20 to go through that line, so what they really wanted was something that was randomly selecting someone 1:20 (or whatever) and not something that was random 1:1 like a lot of people posting in this thread seem to be assuming.

      At the same time, this needs to not have a discernible pattern. Otherwise, the supposed terrorists would know that they'd have some room to spare if they had seen someone be selected for the extra search. They'd have, on average, a minimal of 10 non-extra search slots following each one, though I think the math would show that it would be closer to 20. I'll say 10 just to keep it short and not quibble over the details.

      The assumptions are *NOT* being made by the poster I'm responding to, by the way. Sadly, I have to make that clear.

      They're not randomly selecting if a person is going to go through the line so much as they're randomly selecting which, of X number of people, person is going through the line. I didn't feel like making multiple posts so I'm stuffing the two together and calling it good. I'm lazy today.

      And, on a personal note - not really related to this, they don't want random at all. Random is FUCKING STUPID! They damned well should be profiling. They should be selecting people based on certain criteria. They should be giving extra scrutiny to people who appear nervous, appear to be traveling alone, are not carrying much baggage, bought a one way trip, etc... That might mean that they're even picking people who appear to be of a certain religious persuasion or color. Security really doesn't give two shits about being politically correct, now does it? No, it does not.

      Alas, that's a subject for a different day.

      --
      "So long and thanks for all the fish."
    11. Re:Standard C library... by david_thornley · · Score: 2

      A) Radioactive decay is probably truly random, and you can get generators based on it for a lot less than $1.4M.

      C) Assuming random selection with a fixed probability, it doesn't matter whether the terrorists are lined up consecutively or not.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
  4. Maybe by Anonymous Coward · · Score: 3, Insightful

    "as most programming languages of choice have a randomizing function available to use"
    You mean has a psudo-random function that is not that hard to predict.
    Casino Level Randomization is a little harder.

    1. Re:Maybe by Anonymous Coward · · Score: 5, Informative

      A little harder, yes, but not by much.

      I work on regulated casino software. And we use the Mersenne Twister rather than any sort of dedicated randomization hardware.

    2. Re:Maybe by Anonymous Coward · · Score: 5, Informative

      Some casinos are using actual quantum RNGs. For $1k I can get a USB RNG that emits one photon at a time and a polarized mirror with a perfect 50% chance to go through or reflect off of. 4Mbit/s of RNG. For $35 you can get a pretty strong opensource USB RNG that uses a combination of several quantum level electric, electro-thermal, and EM noise. http://www.bitbabbler.org/

    3. Re:Maybe by Anonymous Coward · · Score: 3, Insightful

      Reset the seed to the millisecond the button was pressed each time it's pressed. Its breakable, but if you can bribe the guard to time it exactly, you can also bribe him to simply put you in one line regardless of what the app says. If you can't bribe the guard, good luck syncing the device's time and trying to social engineer the guy to press the button at an exact moment.

    4. Re:Maybe by TechyImmigrant · · Score: 4, Informative

      Some casinos are using actual quantum RNGs. For $1k I can get a USB RNG that emits one photon at a time and a polarized mirror with a perfect 50% chance to go through or reflect off of. 4Mbit/s of RNG. For $35 you can get a pretty strong opensource USB RNG that uses a combination of several quantum level electric, electro-thermal, and EM noise. http://www.bitbabbler.org/

      All nondeterministic RNGs are quantum in nature. All physical things are.

      What people mean by quantum RNG is actually that they are isolating a single quantum event from all the others. So it has a nice distribution. Only this does not happen. As far as I've been able to ascertain (and it's my job to know) all quantum RNGs are measuring the sum of multiple events and so getting a binomial distribution that then needs a traditional entropy extraction algorithm to get to data with nondeterminism, a uniform distribution and something close to 100% Renye min entropy. This is therefore no different to normal RNGs except there's a smaller number of things in the core nondeterministic process.

      For $0 extra, you can use the RNG in your computer. They're pretty good these days.

      --
      I should use this sig to advertise my book ISBN-13 : 978-1501515132.
  5. Re:Obviously they had to pay a lot by TWX · · Score: 4, Insightful

    I know you're being silly on purpose, but would a true randomizing device really be necessary? Human traffic patterns already have such a random element to them that even if one somehow could reliably predict the next number in the software algorithm, there are so many other factors that can't be controlled that it's still essentially random anyway.

    I honestly could see it being in the low five-figures to develop such an application, but that money would mostly be applied to figuring out how to design the user-interface of the application such that it best-fits with how the TSA is *supposed* to operate, and in beta-testing to confirm that it does what it's supposed to do and that any untrained TSA agent down to the junior-assistant-trainee who breathes with his mouth open could use it and understand it, but mid-six-figures is pretty ridiculous.

    --
    Do not look into laser with remaining eye.
  6. Training? by Feral+Nerd · · Score: 4, Interesting

    The TSA's employees need training on an app that randomly tells people to go left or right?

  7. Nice nonsensical article. by Anonymous Coward · · Score: 5, Insightful

    ZOMG $1.4M for an app that randomizes a single bit!!! (*)

    * Note that it may have actually been $1.4M for hardware, training, and app.

    Seriously, how fucking asinine are these clickbait articles getting? If you can decisively say that they charged $300k+ or $1.4M+ for an app that simple, do so. Otherwise you're just full of shit.

  8. When Mr. Trump says fraud and waste .... by Trachman · · Score: 4, Interesting

    He means precisely instances like that. One needs to find a more idiotic view: the app tells TSA person which way to show the finger. If anybody wants an example of fraud, waste and abuse: this is it. We could listen ad nauseum to TSA explanations, saying that app needs to be secure, or that they have to follow the procedures, or they needed many licenses.... blah blah blah

    The point is that if airport security would be private that kind of nonsense would not exist by definition. Now it is public money that were spent.

    This is not the only software that uses random function. There is another software that randomly selects passengers for additional screening. Here is how Israel does it, does it for free and very effectively: they let the screening agents to pick and choose any passenger that they want or have a hunch. So fare they are very effective in preventing bad dudes in boarding their planes.

    1. Re:When Mr. Trump says fraud and waste .... by E-Rock · · Score: 2

      Except this is America, and the TSA seems to pick from the bottom of the barrel, so your plan would just result in extra 'screening' for all the hot chicks? If you think that's absurd, see how good a job they did picking who to run through the body scanners.

    2. Re:When Mr. Trump says fraud and waste .... by beelsebob · · Score: 3, Insightful

      He means precisely instances like that.

      The problem is, that what he proposes, is more of this... He proposes that more of the country should be privatised, because "businesses can do it much more efficiently".

      The correct solution here was not to get any business involved at all, because as soon as you do that, they try and make a (huge) profit out of it. The correct solution was instead to get a software engineering intern on the government's payroll to write this app in one day.

  9. Re:Training? by BeauHD · · Score: 2

    This may be the most surprising tidbit in the article.

  10. Sounds about right by Onthax · · Score: 2

    Honestly having worked with government, it sounds about right probably a 1000 hours of meetings to choose the colours, shape, discuss the randomizing algorithm etc. prob took no time at all to write.

  11. Re:Training? by Anonymous Coward · · Score: 2, Funny

    The TSA employees first needed to be trained to understand "left" and "right".

  12. Re:Why do you need an iPad and an app? by John+Bresnahan · · Score: 4, Informative

    A simple micro-controller, a button, and two LEDs would work just as well for just a few bucks.

    A die (singular of "dice") would work just as well, and would handle up to 6 checkpoints.

    Amazon has them, 100 for $2.79.

  13. Rules and Regulations by TechyImmigrant · · Score: 5, Insightful

    Are you selling it to the federal government? [YES]
    Is a random number generator used in the product? [YES]
    Is the product intended for a security application? [YES]

    Requirement: The Random Number Generator be CAVS certified to SP800-90A and the module within which is operates be FIPS140-2 certified.

    That's $100,000 before you've got out of bed, to meet the government procurement requirements.

    --
    I should use this sig to advertise my book ISBN-13 : 978-1501515132.
  14. Why am I working for a living? by kheldan · · Score: 2

    I read stuff like this and it makes me question having ethics and conscience.

    --
    Are YOU using the TOOL, or is the TOOL using YOU? Think about it!
  15. Re:Training? by argumentsockpuppet · · Score: 5, Insightful

    It's possible IBM supplied all the iPads and training in addition to the app itself.

    I know it is fun and easy to criticize the TSA, and I am in favor of replacing them entirely with any of a dozen different possibilities. That said, there is a big difference between developing an app and supplying hardware and doing testing and training. I could build the app but I have no idea what the cost would be to test it sufficiently to meet government standards, then train the staff to use them, then equip the staff with hardware to use it. The cost of the app could literally be $0 and still top $1 million after the testing, training and equipment costs.

    Someone else pointed out this is typical clickbait. It's got a shocking headline but then scant details on what actually caused the scenario. If they'd instead said "TSA has IBM develop an app that IBM contributed for free in exchange for exclusive rights to train staff for $10/hr each on how to handle customer service. Additionally, IBM will supply sufficient devices to have a minimum of two for each airport line at 5% profit per device" then the headline wouldn't generate nearly so much interest and the criticisms would be much better founded.

    I wouldn't be at all surprised to find out that the bureaucracy that guides the TSA spent far more than is reasonable. I just didn't see enough details in TFA to assume that is actually the case. Does *anyone* have a breakdown on what kind of training, what kind of testing, what kind of devices were purchased?

  16. Re:Training? by Calydor · · Score: 5, Funny

    That was surprising? Have you seen a TSA agent recently?

    --
    -=This sig has nothing to do with my comment. Move along now=-
  17. Re:There already exists a device for this... by Calydor · · Score: 2

    To be fair, can you imagine flipping a coin and flawlessly catching it thousands of times per day?

    --
    -=This sig has nothing to do with my comment. Move along now=-
  18. SchrÃdinger's cat by PPH · · Score: 2

    Build a device with a small radioisotope source, detector, poison vial and cat. Calibrate the source to provide a 50% probability of a particle emission for the average passenger rate. Open the box and check the cat. Cat alive: Right lane. Cat dead: Left lane, reset vial, replace the cat and proceed.

    --
    Have gnu, will travel.
    1. Re:SchrÃdinger's cat by ChunderDownunder · · Score: 2

      Dear slashdot.

      Please fix foreign characters.

  19. Re:Obviously they had to pay a lot by Intron · · Score: 3, Funny

    What happens when ISIS uses one of the well-known DNS holes to redirect http://www.yesnogenerator.com/ to a site that returns the answer that they want? You just let 5 terrorists get through security.

    --
    Intron: the portion of DNA which expresses nothing useful.
  20. Re:Obviously they had to pay a lot by mysidia · · Score: 2

    I know you're being silly on purpose, but would a true randomizing device really be necessary?

    I have a $0.01 alternative to this randomizer app.... Flip a fair coin. Designate one side of the penny Heads, and the other side tails....

    Also, even if they have 50,000 pre-check lanes, the total cost is still only $500.

  21. Re:I'd like to bid next time by Applehu+Akbar · · Score: 2, Insightful

    I have a system that is:
    - Analog
    - Does not require electricity
    - Durable
    - Ambidextrous
    - Gender neutral
    - Made in the USA

    Training video here: http://putlocker.is/watch-goin...

    Dear Mr. Sexconker,

    We are in receipt of your case of 2000 (two thousand) manually operated analog cupronickel randomization discs. We admire the evident durability and domestic origin of your product, and initial testing proves that the sequence of flips is suitably random. In addition, we are confident that your training video can be developed into a course that our agents will be able to complete in about six months.

    Unfortunately, your product does not meet the contracted criterion of gender neutrality. Al of the "heads" depicted are male.

    Yours,
    Monroe Fnord, Technology Director
    Transportation Security Administration

  22. Re:Gimme money by AlexanKulbashian · · Score: 2

    Oops.. the beta version failed to work... here is a revision: rand() % 2;

  23. Re:Obviously they had to pay a lot by Jason+Levine · · Score: 5, Interesting

    I have a $0.01 alternative to this randomizer app.... Flip a fair coin. Designate one side of the penny Heads, and the other side tails....

    I recently read "Lauren Ipsum: A Story About Computer Science and Other Improbable Things" to my eight year old. One of the (many) interesting substories involved "fair coins." Lauren's money isn't taken in Userland because her quarters can't be guaranteed as fair. However, someone points out that you can make any coin a fair coin by flipping it twice. If both flips result in the same side, you ignore it and flip two more times. If the two flips have differing sides, you take the first side.

    In other words:

    Heads-Heads or Tails-Tails = Flip again.
    Heads-Tails = Heads
    Tails-Heads = Tails

    Even if there's a bias towards one side, it will be cancelled out and the flip would be fair.

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  24. Seriously 85% for interacting with gov't by raymorris · · Score: 4, Interesting

    Seriously, 80%-85% of the bid covers dealing with the US government. Multiple thousand-documents over the course of years, flying back and forth for pointless meetings, and maybe you eventually get paid.

    Here are my rates as a developer , for similar software delivered:
    Order online, by submitting my order form: $159
    Email me and discuss: $500
    Meetings to discuss, demo (local businesses): $1,500
    Local government bureaucracy: $8,000
    Federal government: $400,000

  25. Re:Why do you need an iPad and an app? by Jason+Levine · · Score: 2

    I roll to dodge the Rapiscan line. *1* Rats.

    Ok. I roll to dodge to pass the scan without any anomalies. *2* Failed.

    Ok, so anomalies are found. I roll to protect against the TSA pat-down. *1* Failed.

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  26. Re:Why do you need an iPad and an app? by Pseudonym · · Score: 2

    Presumably Pre-Check fliers get a saving throw?

    --
    sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
  27. Re:Obviously they had to pay a lot by Noah+Haders · · Score: 5, Funny

    the actual passenger-facing software was really cheap. what was expensive to develop and install is the cameras and computer detection algorithms to tell if the person is white, black or brown.

  28. It makes sense if you call them by the right name by Required+Snark · · Score: 3, Insightful

    Department of Homeland Pork, Transportation Pork Administration

    --
    Why is Snark Required?
  29. Re:Exploit? by Anubis+IV · · Score: 2

    There are only two cases where exploiting the left/right randomization would matter to terrorists

    1) They already have a means of getting contraband through the screening on one side but not the other, in which case your system is already broken, since the terrorists already have a 50% chance of getting through screening, even if your RNG is working the way you want.

    2) There's a target on the one side but not the other, but if they want to make sure someone hits the target, they can just send a few terrorists through together in the line. Send four in a row and your odds are nearly 95% that at least one would end up on the side you want. And if they're all together, by the time the first one is discovered, the one you wanted would already be at his destination.

  30. Re:Obviously they had to pay a lot by TheRaven64 · · Score: 2

    Why? Let's say it's the probability is 0.7 of head, 0.3 of tails. The probability of head-heads is 0.7*0.7. The probability of tails-tails is 0.3*0.3. The probability of heads-tails is 0.7*0.3. The probability of tails-heads is 0.3*0.7. 0.3*0.7 = 0.7*0.3, so the probability of heads-tails is equal to the probability of tails-heads.

    This assumes that the coin tosses are independent.

    --
    I am TheRaven on Soylent News
  31. Re:Obviously they had to pay a lot by KGIII · · Score: 2

    > Human traffic patterns already have such a random element to them

    You'd think so. It's not. Neither vehicular nor pedestrian traffic is random. There is order to that chaos, it's just not easy to find and the herd is easily spooked.

    I lack the time and energy to get into the gritty details but I've gone into this quite a bit in the past. Feel free to scrounge through my posting history if you want. I modeled traffic (vehicular and pedestrian) and I'm pretty sure that it is chaotic but not truly random.

    It may appear random, it is not. How to describe it quickly.

    Okay, try this... Go to your nearest mall or department store - you might want to go to a few. Watch the people when they enter. If given a choice, they will (almost invariably) opt to go to the right. Stores, those who wish to curate the experience, will actually work to *force* you to go to the right. For example, they'll often have the bakery to the right - and lots of colorful objects. Why? Lots of reasons but because it's not *always* true that people go to the right - but it's true (far) more often than not.

    It doesn't seem to matter if the person favors one hand over the other, or is "goofy footed" or not, nor does it seem to have much cultural variation. Chances are REALLY high that you'll go to the right. The odds favor it so heavily that it's the assumed default and they'll literally make changes to a store's layout to force compliance - with some notable exceptions that are too long to detail here but include things like a pharmacy within the same store. They want you on that route because they don't want you to be able to quickly grab your needed/most often purchased items quickly and then leave.

    It's a lot of data. It's very chaotic. It's not random - not even remotely. Done well, you won't even notice. It's even true at outdoor events, in large auditoriums, and in sporting arenas. We don't know why this is true but, unless the data has changed in the past eight years, we humans are particularly fond of going to the right. There are a variety of other things to "count on" as a whole but it's not something I'm going to delve into in this post. I lack time and energy. That's one (of many) examples.

    There are many patterns and near-universal truths but you have to step back and make observations and have a whole lot of data before some of them become apparent. By a whole lot of data, I mean a whole lot of data. By the end of the 1990s it was to the point where we were using disk arrays that were a full terabyte in size. That might not seem like a lot but, going by estimates with your UUID, look at the time period that was and think about how much a TB really is. (It was also not very cheap back then.)

    --
    "So long and thanks for all the fish."
  32. Re:Obviously they had to pay a lot by lord+merlin · · Score: 2

    I know you're being silly on purpose, but would a true randomizing device really be necessary?

    I have a $0.01 alternative to this randomizer app.... Flip a fair coin. Designate one side of the penny Heads, and the other side tails....

    Also, even if they have 50,000 pre-check lanes, the total cost is still only $500.

    Sell the pennies to the government for $10 apiece.

  33. Re:Obviously they had to pay a lot by Gamasta · · Score: 4, Insightful

    "IMO the gaps between the rationals are small enough that it doesn't matter if you can prove this for irrationals"

    Excuse me, but your opinion is wrong. Rational numbers are said to be sparse in the real number space. For the argument see "Lebesgue Measure." As for why there are more irrational numbers than rational numbers see "Cantor's diagonal argument".

    Your reasoning is however correct. If P(HEADS) = p, P(TAILS) = (1-p). The probability for coin tosses are:
    HH = p*p
    HT = p(1-p)
    TH = (1-p)p
    TT = (1-p)(1-p)

    Eliminating HH and TT leaves HT and TH at p(1-p) probability. There's no assumption on p being rational or not. However the further you are from p=0.5, the longer it takes to get a "valid" flip.

    --
    reason defies logic
  34. Re:Obviously they had to pay a lot by tburkhol · · Score: 2

    Go to your nearest mall or department store - you might want to go to a few. Watch the people when they enter. If given a choice, they will (almost invariably) opt to go to the right.

    I wonder if you would get the same result in the UK or Australia.

    But that's not the kind of 'random' at issue here. They're talking about the clock time when a person standing in a line triggers a sensor. For any sensor of human-sized objects moving at TSA-line speeds, I would expect sensor variability to be a large part of the "is the current millisecond even or odd" decision.

  35. Expensive for good reason? by GameboyRMH · · Score: 2

    [Tinfoil] It's not a real randomizer app, it's an advanced layered neural network program (IBM...Watson?) that automates racial profiling so that TSA workers are in the clear, they can say the machine made the decision for someone to go through heightened security, "at random." Teaching the program to pick out the right minorities took a lot of work. [/Tinfoil]

    --
    "When information is power, privacy is freedom" - Jah-Wren Ryel