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LA Airport Uses Random Numbers To Catch Terrorists

Posted by CmdrTaco on from the better-than-searching-me-whenever-i-have-a-beard dept.

An anonymous reader writes "Los Angeles International Airport (LAX) is using randomization software to determine the location and timing of security checkpoints and patrols. The theory is that random security will make it impossible for terrorists to predict the actions of security forces. The ARMOR software, written by computer scientists at the University of Southern California, was initially developed to solve a problem in game theory. Doctoral student Praveen Paruchuri wrote algorithms on how an agent should react to an opponent who has perfect information about the agent's choices."

2 of 321 comments (clear)

  1. Re:Doesn't Microsoft hold patents on that? by jkrise · · Score: 4, Informative
    actually the Excel bug was a rendering bug, the actual calculated value was correct, to prove this, take the output that is visually wrong in the cell and use in a further calculation. You will the result is correct....

    Wrong! It is random, actually. It's right there in the summary of the /. artice:

    "Suppose the formula is in A1. =A1+1 returns 100,001, which appears to show the formula is in fact 100,000... =A1*2 returns 131,070, as if A1 had 65,535 (which it should have been). =A1*1 keeps it at 100,000. =A1-1 returns 65,534. =A1/1 is still 100,000. =A1/2 returns 32767.5." So it's just not a simple rendering bug... on random ocassions, it calculates further using the faulty value.
    --
    If you keep throwing chairs, one day you'll break windows....
  2. Not elementary! by Ambitwistor · · Score: 4, Informative

    Randomize checking so that an attacker can't predict the next check and avoid it? That's what I would do, too. Can I be a high-paid security consultant now? The point is not that the strategy is random, but that the randomization is optimized to be robust against an adversary who knows what your randomization scheme is. That's what the game theory is for: it's a classic mixed strategy.

    Remember, there are many ways to be random: check area X Y% of the time; perform check W Z% of the time, etc. What should Y and Z be? How do you balance the occurrence of Type I and Type II errors? Some strategies are better than others: there's a reason why game theory was invented.

    Try reading the study; the results are not trivial.