Software to Randomize Police Operations at LAX

owlgorithm writes "A USC research group has created software, named ARMOR (Assistant for Randomized Monitoring over Routes), that will be used at LAX Airport to make security and police operations there truly unpredictable. The software records the locations of routine, random vehicle checkpoints and canine searches at the airport, and police provide data on possible terrorist targets, based in part on recent security breaches or suspicious activity. The software then makes random decisions (which are thankfully based on calculated probabilities of terrorist attacks) and tells the police where to dispatch and when. The most notable detail is that terrorists who had access to ARMOR still wouldn't be able to predict the searches."

Even the terrorists can't predict it!

[Anonymous Coward]

The most notable detail is that terrorists who had access to ARMOR still wouldn't be able to predict the searches."

Unless, of course, the terrorists are in the USC research group and they left a fatal flaw or backdoor inside!

Re:Wait!

[davetd02]

So it's not really random... A pattern must come out after a while.

Not at all. A "pattern" that's useful to a criminal would be knowing that there's always a checkpoint on Lane 1 on Mondays, or that they always check Lane 4, then Lane 2, then Lane 1, then Lane 3.

Using the probabilities means that at any given moment there's a 20% chance they'll be checking Lane 1 and a 30% chance they'll be checking Lane 2, but it doesn't tell you whether you should try to smuggle contraband through 1 or 2.

It's basically ideal game theory -- even if the other side knows what your algorithm is, they can't beat it since you're still playing randomly. The usual Computer Science example is a tennis player; you know there's a 60% chance that your opponent will hit it to your backhand and a 40% chance that they'll hit it to your forehand, but there's a limit to how far you can compensate either direction. Knowing the probability in that case doesn't tell you which side the ball is going to go to. (The real example is somewhat more convoluted, but you get the 10-second version)

Re:Random?

[hardburn]

There are plenty of ways to get true randomness using hardware. Keyboard click timings, hard drive seek time, radioactive decay monitoring (probably the best, since its based on quantum nondeterminism), capacitor level checking, CCD camera in a dark coffee can, and a bunch of others. No pure software solution exists, though.

Re:Weighted?

[Anonymous Coward]

The weighting should be by the amount of damage the terrorists can inflict at each point. This way the total risk of damage is minimized: you check more often at more critical points, and less often in unimportant areas.

More complicated models can be created by taking into account that the guards can see neighbouring areas while going along their route, and by considering multi-stage terrorist attack scenarios. There's a lot of research to be done at government dime here!

Solution

[Plazmid]

There is a simple solution to this problem, don't use software to do the randomizing. A D20 and a book of rules are fairly resistant to hackers. In others words, if you roll a 4 or a 5 search person otherwise don't.

Re:Why spend the money?

[Heembo]

Except for that sniper who sits in the upper right hand corner of the international terminal. He let me see his gun once and explained to me what a top notch shot he was. DANG that boy is NOT joking around!

Re:Can you spell "Hacker"?

[mlts]

That is an interesting modification. All it would take is substituting their existing (hopefully cryptographically secure RNG) with a random seeming PRNG that is very predictable, such as AES-ing output from /dev/zero with an all zero 128-bit cypher key. The output looks random to the people being assigned to the sweep teams, but for the attacker, he or she will know exactly where they are... and are not.

I just hope the ARMOR system is (excuse the pun) well ARMORed against attacks, both local and remote.

Re:better idea

[gbobeck]

all terrorists have to do is send enough people at the same time and the chances are, one will get through./blockquote
Ah, the Mongolian Terrorist Horde technique.

Of course, if terrorists were actually serious about an attack they could simply skip trying to get a bomb onto an aircraft and instead do one of the following:

1. Shoot an aircraft down from outside the airport.
2. Detonate an explosive device in front of a security checkpoint or ticket counter in the unsecure zone of the terminal during a busy time when the lines are long.

Re:Wait!

[archeopterix]

But it does tell you that your most optimal move is to expect them to hit it to your backhand. It'll tell the terrorists that Lane 1 is the best one to attempt to get through, statistically.

The 'best choice' paradox is the exact reason for intruduction of randomization. It goes like this: suppose that lanes have different payoffs for the successful smuggler - maybe because they go to (or from) countries that have different street prices of 'goods'.

The smuggler knows that Lane 1 gives the best payoff, so he will try that one, but the customs people also know that, so they will check that one. Hm... but the smuggler knows that they know, so he'll try Lane 2 (the second best), but the customs people also know that, and the smuggler knows that too, so he will try the 1st one... Well, to make long story short, the best strategy for both sides is to use randomization, with probabilities calculated so that the expected payoff for the opponent is minimized.

Another Idea

[lbgator]

I know this article deals specifically with airport police where you want their actions to be truly unpredictable. What about regular beat cops though? Do we want them to be in random places daily?

I often see cops hiding in random places trying to catch speeders, and I wonder if that is the best use of their time. On one street near me there is a speed trap weekly. I suspect this is because the speed limit is 30 mph going down a moderately steep hill so it is easy to catch speeders. As a citizen I would rather these cops be doing nearly ANYTHING else (to include volunteering at a school or working out). I am not at all concerned about someone going 36 in a 30 - I am concerned that my tax dollars are paying to enforce a rule that helps nothing (in my opinion).

Now, the standard answer is "well if they stop speed trapping then everyone will speed". I totally agree: the rules are good in general. How about a nation wide database that records all accidents, crimes, and public complaints. That way the police could focus all of their attention in the spots where there is trouble or complaints. If the local teen punk is speeding through your neighborhood post a complaint - then cops can respond in the best way they can. As it is there is very little police interaction with the public - they have no resort but to randomly hide in bushes and try to surprise us. A database that tells them trouble spots to focus on would make their jobs more justified. And in a town/area that goes without crime, accident, or complaint for a certain period could allow the cops to volunteer at a high school or coach youth soccer or pick up trash or something that the citizens actually appreciate.

Unpredictable cops are fine in the airport - but if I am acting reasonably responsible in a trouble free area I'd like to keep my interactions with the police to a minimum.