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Matt Blaze: How unpredictable screening helps terrorists

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Re: Matt Blaze: How unpredictable screening helps terrorists

#61

Post by ghshephard »

blasdel wrote: post #45
ghshephard wrote: post #30

Earlier quoted context omitted.

Kip Hawley, former head of the TSA has answered this question a number of times, including conversations with Schneier. Most of the liquids that can do the type of damage the TSA are concerned about are likely highly oxygen reactive, or otherwise have significant obstacles to being combined outside of a lab environment. If that weren't the case, the TSA would have simply banned all liquids.

Why would you have to combine the liquids into one reservoir? Couldn't the N passengers just make N bombs from their 3x 3oz, each independently capable of going off, but intended to be detonated together for maximum effect?

If the TSA is acting rationally, and I have to believe they are, I would have to believe that the ingredients can't be combined outside of a lab, or trivially in a washroom. Otherwise you are right - you don't even need to have more than one person on the plane carry the dangerous liquid, in fact, you wouldn't even need the person about to blow up the plane carry the liquid - just have three or four people taking planes to random areas get together, reformulate the bomb, and then hand it off to person number five who is clean.

Of course, we're now talking about a _conspiracy_ - and a conspiracy of four average people is 100x more likely to be discovered by a intelligence team than a single attacker.

So perhaps it's the forcing of attacks to be _conspiracies_ is the goal of allowing only small amounts of liquids.

Regardless - I think we can all agree that it makes liquid bomb attacks substantially more difficult than simply allowing people to carry on as much liquid as they chose, and therefore opening the door wide open to a lone attacker just blowing up airplanes at will without possibility of detection.

Re: Matt Blaze: How unpredictable screening helps terrorists

#62

Post by jeremyw »

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…

He always seems to fail to recognize the principles of defense-in-depth...

That's a broad claim given that Schneier's built his reputation/business around defense-in-depth. It's practically his hobby horse and I don't read any such misunderstanding in his essays on the TSA.

Re: Matt Blaze: How unpredictable screening helps terrorists

#64

Post by dandelany »

CamperBob wrote: post #55
sethg wrote: post #19

the best terrorist strategy (as long as they have enough volunteers) Do they have enough volunteers? The Shoe Bomber and the Undie Bomber, compared with the team that pulled off 9/11, are a couple of amateurish mooks. If these are the best men that al-Qaeda can send against the United States, they must not have a very deep bench.

That's just it... the people who pulled off 9/11 were a bunch of amateurish mooks. A bunch of amateurish mooks with an 18 in the Luck department is still dangerous. Just as in this case, there were any number of measures already in place that could have stopped 9/11, if they had only been followed. More rules are not the answer.

Well, sort of. They were 19 amateurish mooks who had gone to flight school. That's a far cry from a couple of idiots with unsuccessful bombs.

Re: Matt Blaze: How unpredictable screening helps terrorists

#65

Post by ghshephard »

jeremyw wrote: post #62
ghshephard wrote: post #27

Earlier quoted context omitted.

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…

He always seems to fail to recognize the principles of defense-in-depth... That's a broad claim given that Schneier's built his reputation/business around defense-in-depth. It's practically his hobby horse and I don't read any such misunderstanding in his essays on the TSA.

Of course he has built his reputation on it - I've probably learned half of what I know about defense-in-depth from Schneier. The thing is, when it comes to aviation security, he has a tendency to discount the importance of preventing bad things from getting on airplanes, and over emphasize the importance of preventing bad people from getting on airplanes.

I think they are both important. The TSA clearly thinks the "prevent bad things from getting on airplanes" is a more containable problem. We have the NSA/CIA/FBI and other intelligence services that will work on the bad-people problem, which in no way means we can't simultaneously dedicate resources to the "bad things on airplane problem."

As an aside, our last line of defense is clearly "Prevent Bad people from doing bad things on airplanes" - which is how both the christmas underwear bomber and the shoe bomber were stopped.

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