Matt Blaze: How unpredictable screening helps terrorists • Hacker News Board

Re: Matt Blaze: How unpredictable screening helps terrorists

#31

Post by tptacek » Thu, Dec 31, 2009, 8:42 PM UTC

rogersm wrote: post #21

alterego wrote: post #20

Earlier quoted context omitted.

But if you read the article, I believe the point was that if the terrorist gets caught under a random system, the terrorist still achieves a positive result for the terrorists (the govt becomes forced to shut down aviation and then apply the maximum screening to everyone, causing expensive chaos and terror of its own).

This is not the kind of chaos of terror the terrorist has on his mind. Otherwise they will be shutting down traffic light control systems. Getting caught is a failure. A bomb exploding is a victory.

Getting caught this time was a huge win. By all accounts, the guy who got caught was a nobody. Had he even been to the camps for training? For the cost of a pair of explosive underpants and the life of one shmuck, AQ is once again top-of-mind in the west --- not to mention the tens of millions of dollars of disruption the stunt caused.

There is a practically limitless supply of shmucks out there for AQ to weaponize. All they have to do is get better at converting them. What evidence do we have that this will be a long-term operational problem for AQ? Everything I see indicates that they will get better at it, not worse.

This is also why they aren't shutting down traffic lights. A failed attempt to shut down traffic lights wins nothing. Nobody is viscerally afraid of darkened traffic lights. In fact, until it happens, nobody is going to be viscerally afraid of someone taking out the grid. But everyone is afraid in their gut of exploding planes. Just the threat --- just 5% of the threat --- is enough to wreak havoc.

Re: Matt Blaze: How unpredictable screening helps terrorists

#32

Post by ghshephard » Thu, Dec 31, 2009, 8:43 PM UTC

rogersm wrote: post #15

tptacek wrote: post #6

Earlier quoted context omitted.

The idea that Matt Blaze thinks the three-ounce rule is sensible was surprising to me; I hit it, jumped back to the top, and re-read the whole article. What's the flaw in his reasoning? The three-ounce rule always seemed like one of the more ridiculous TSA measures.

After all, the latest bomber was carrying 80 grams, less than three ounces.

Note that it was 80 grams of _powder_, not liquid.

Re: Matt Blaze: How unpredictable screening helps terrorists

#33

Post by ghshephard » Thu, Dec 31, 2009, 8:47 PM UTC

chaosmachine wrote: post #14

tptacek wrote: post #12

Earlier quoted context omitted.

WHY? Really, how much do you think a PETN bomb costs? Re-read the article: nothing that happens in response to these attacks fails to help the terrorists. They send 5 people and one blows up a plane: huge positive ROI . They send 5 people and nobody blows up a plane, but commercial air travel is disrupted to the tune of hundreds of millions of dollars: huge positive ROI .

You have a good point, if you measure it in terms of financial damage, the terrorists win either way. A side point: I suspect bombs are at bottom of the price chart in terms of financing an attack. More likely, the most expensive part is finding someone stupid enough to blow themselves up, and getting them to the right place at the right time. The cost of doing this undetected would probably increase non-linearly wit…

The good news for our side, is that these people have to be simultaneously stupid enough to blow themselves up, yet bright enough to make it through security. This is why El Al's approach to security (personal interviews with all passengers) is effective - you'd have to be close to genius level to get through their screening without triggering a (real-world, not TSA-Pansy) pat-down and luggage check - at which point, if you were that bright, you probably wouldn't be volunteering for kaboom duty.

Re: Matt Blaze: How unpredictable screening helps terrorists

#34

Post by tptacek » Thu, Dec 31, 2009, 8:48 PM UTC

ghshephard wrote: post #27

tptacek wrote: post #5

This article demonstrates what I like about Matt Blaze's physical security writing that I don't like about Schneier's. Both are computer security experts by training, but Blaze's writing has a concrete engineering-driven perspective that Schneier's lacks. Schneier's writing always "feels" right, but leaves you with the sense that's it's not based on any operational reality. It's probably not a coincidence that Matt B…

Another thing to note - Matt Blaze typically approaches security scenarios with a different cost/benefit perspective than Schneier, for example Blaze writes: "The TSA's much maligned "three ounce" liquid rule is, in fact, a nice example of good security engineering of this kind. " Schneier, on the other hand, considers the inconvenience to travelers to be not worth the hassle. He always seems to fail to recognize the…

Maybe it's just that Blaze's stuff seems falsifiable, and Schneier's stuff is slippery and abstract. At least we can argue rationally about the three-ounce rule. But if you accept Schneier's argument, there's no incremental discussion to be had.

Even if I agree with that (I do more than I don't), it's not productive. Regardless of whether "it's time for the TSA to go" (+34 yesterday last time I checked), the TSA isn't going anywhere. Shut up?

Re: Matt Blaze: How unpredictable screening helps terrorists

#35

Post by ghshephard » Thu, Dec 31, 2009, 8:54 PM UTC

tptacek wrote: post #28

rogersm wrote: post #17

Earlier quoted context omitted.

First of all I must say I don't believe in these kind of unpredictable systems: rarely doing this 'select randomly the process from a set of processes' works better than using the best process in the set. But I don't think this applies: But terrorist organizations -- especially those employing suicide bombers -- have very different goals and incentives from those of smugglers, fare beaters and tax cheats. Groups like…

Ramping up a new KSM has a high cost. Ramping up a mujahedeen to skirmish with NATO in Khost has a high cost. Ramping up the guys who know how to rig PETN bombs has high cost. Ramping up guys who can operate safe houses and route money through a paranoid cell system has a high cost. Building the system has a high cost. Using the system to exploit the dumbfucks who get captured by the system in order to get them to pu…

I disagree with your premise that a comparison can be made between SPAM and Sending-terrorists into the American Aviation system. SPAM is cheap because it is simply software than can be used to send out billions of copies. The number of possible jihad-motivated individuals that can be sent into the American Aviation system, between the screening, visa, and no-fly/selective screen lists (that you just _know_ are about to get a lot more aggressive in the next 90-120 days) is pretty limited.

There just aren't that many jihadists that will be allowed to fly without a lot of careful screening anymore.

Particularly after international airlines now have some experience with patting down and inconveniencing _all_ of their customers as a result of missing the christmas underwear bomber - there is now a pretty good incentive for them to start being cautious about those who were in gray area previously. No more gray area - if there are doubts (I.E. you are on the TIDE list) - you get checked carefully.

Re: Matt Blaze: How unpredictable screening helps terrorists

#36

Post by tptacek » Thu, Dec 31, 2009, 9:01 PM UTC

ghshephard wrote: post #35

tptacek wrote: post #28

Earlier quoted context omitted.

Ramping up a new KSM has a high cost. Ramping up a mujahedeen to skirmish with NATO in Khost has a high cost. Ramping up the guys who know how to rig PETN bombs has high cost. Ramping up guys who can operate safe houses and route money through a paranoid cell system has a high cost. Building the system has a high cost. Using the system to exploit the dumbfucks who get captured by the system in order to get them to pu…

I disagree with your premise that a comparison can be made between SPAM and Sending-terrorists into the American Aviation system. SPAM is cheap because it is simply software than can be used to send out billions of copies. The number of possible jihad-motivated individuals that can be sent into the American Aviation system, between the screening, visa, and no-fly/selective screen lists (that you just _know_ are about…

You keep using this word "jihadist" as if the people on the flights have spent a year running obstacle courses and stripping down kalashnikovs in the camps in Waziristan. That's not who they'll put on the planes. For every AQ op that can shoot straight, somewhere in the world there are 100 shmucks that can put a pair of underpants on and board a plane.

All AQ has to do is get better at taking mentally unstable people from unstable parts of the world and pointing them in the right direction. 90% of them will fail. Hell, 99%. But the 1% that succeed will make us react horribly to the other 99%.

Re: Matt Blaze: How unpredictable screening helps terrorists

#37

Post by pedrocr » Thu, Dec 31, 2009, 9:10 PM UTC

The problem is that with non-random screening the terrorists can be much more efficient. They can get a pool of candidates together and send them on flights without any explosives on them. They can then find out which of the guys get screened at a rate less than chance and send those on the actual attack. That's why random screening is the best system possible because any other system would have to be perfect, otherwise any flaw can be detected on dry runs and exploited for the attack.

This was thoroughly explored last time the TSA tried to be smart about screening and implemented its Computer-Assisted Passenger Screening System. MIT article exploring it:

http://groups.csail.mit.edu/mac/classes/6.805/student-papers...

Re: Matt Blaze: How unpredictable screening helps terrorists

#38

Post by alterego » Thu, Dec 31, 2009, 9:20 PM UTC

pedrocr wrote: post #37

The problem is that with non-random screening the terrorists can be much more efficient. They can get a pool of candidates together and send them on flights without any explosives on them. They can then find out which of the guys get screened at a rate less than chance and send those on the actual attack. That's why random screening is the best system possible because any other system would have to be perfect, otherw…

I think this article isn't talking about random vs. profiled (which is what the mit paper is about), but random vs. 100% (where there 100% has been analyzed carefully to be sufficient to detect large bombs, etc.).

Re: Matt Blaze: How unpredictable screening helps terrorists

#39

Post by pedrocr » Thu, Dec 31, 2009, 9:24 PM UTC

alterego wrote: post #38

pedrocr wrote: post #37

The problem is that with non-random screening the terrorists can be much more efficient. They can get a pool of candidates together and send them on flights without any explosives on them. They can then find out which of the guys get screened at a rate less than chance and send those on the actual attack. That's why random screening is the best system possible because any other system would have to be perfect, otherw…

I think this article isn't talking about random vs. profiled (which is what the mit paper is about), but random vs. 100% (where there 100% has been analyzed carefully to be sufficient to detect large bombs, etc.).

He was hand-waving at the end about the 100% but that's not a solution. They are doing it randomly because 100% is simply not possible. My point was that in a situation where 100% is not possible, as in real life, any system is potentially worse than randomness.

Maybe this just means we need to come up with screening mechanisms that can be applied to 100%, but given the current capabilities, choosing random screening is better than profiling.

Re: Matt Blaze: How unpredictable screening helps terrorists

#40

Post by ghshephard » Thu, Dec 31, 2009, 9:34 PM UTC

tptacek wrote: post #36

ghshephard wrote: post #35

Earlier quoted context omitted.

I disagree with your premise that a comparison can be made between SPAM and Sending-terrorists into the American Aviation system. SPAM is cheap because it is simply software than can be used to send out billions of copies. The number of possible jihad-motivated individuals that can be sent into the American Aviation system, between the screening, visa, and no-fly/selective screen lists (that you just _know_ are about…

You keep using this word "jihadist" as if the people on the flights have spent a year running obstacle courses and stripping down kalashnikovs in the camps in Waziristan. That's not who they'll put on the planes. For every AQ op that can shoot straight, somewhere in the world there are 100 shmucks that can put a pair of underpants on and board a plane. All AQ has to do is get better at taking mentally unstable people…

Per - Jihad: The Origin of Holy War in Islam. Oxford University Press

'The term "Jihad" used without any qualifiers is generally understood in the West to be referring to holy war on behalf of Islam.'

What I'm trying to state is that the number of individuals who have radicalized to the point at which they will blow themselves up AND are authorized to fly on the American Aviation system, are few and far between. Even the christmas underwear bomber had been reported to both the CIA and State Department. If they had simply taken the father at his word "My Son is radicalized islamist and has a Visa which permits him to fly into the USA" they would have put him onto a list of selective screening and a bit of an extra pat-down, if not revoked his Visa in the same manner as the UK.

You can be certain that the TIDE list is going to be aggressively reviewed, and the list of 14,000 or so people currently targeted for selective screening is going to grow dramatically in the next few months.