Matt Blaze: How unpredictable screening helps terrorists
crypto.com
crypto.com
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 Blaze has done formal research on physical security topics (safecracking, wiretapping, etc) --- in addition to being a bona fide computer scientist.
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 Al Qaeda aim to cause widespread disruption and
terror by whatever means they can, even at great cost to
individual members. In particular, they are willing and
able to sacrifice -- martyr -- the very lives of their
solders in the service of that goal. The fate of any
individual terrorist is irrelevant as long as the loss
contributes to terror and disruption.
So random screening works, not because that influences the behavior even of those who aren't checked, but because makes executing the attack more expensive to overcome the possibility of being detained in the random test.
Of course random screening is not as good as full screening, but from a realistic point of view is the only thing you can apply without shutting down world economy.
Getting caught is a failure. A bomb exploding is a victory.
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.
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 put the explosive underpants on is cheap.
If the system was jeopardized by any terrorist attempt, you'd be right. But it isn't. It's like spam. It may have a 0.001% conversion rate, but as long as it pays off 10000000:1, it's sustainable and resilient.
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.
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%.
Perhaps even most fanatics and angry unstable people prefer to shoot at soldiers than take a 99-in-100 chance of winding up in infidel custody, famous only in failure.
'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.
They really need to make this a list of names/photos instead of just a list of names. The idea that we can target terrorists with a 'no-fly list' based entirely off of someone's name and not the mugshot is absurd.
While a one-in-a-twenty chance of success sounds good from a terror chief's perspective, no suicide bomber wants a 95% chance of winding up in captivity, famous only as a failure. Out of the twenty, they want to be the one!
So plans that allocate many participants to expected capture will have far fewer volunteers. And every report of a capture will decrease potential-volunteers' willingness to sign up, because they will adjust upward their expectation of embarrassing capture rather than martyrdom.
There's also a tradeoff between their naivete and effectiveness: a bumpkin who's never traveled internationally might believe whatever his handlers tell him, but is also more likely to draw suspicion or otherwise foul the mission.
"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 principles of defense-in-depth, and over-emphasizes the importance of stopping the terrorist before they launch an attack. I say this as someone who has ready pretty much every essay and book he has ever written, sometimes multiple times.
For example:
http://www.schneier.com/blog/archives/2006/08/terrorism_secu...
". Banning box cutters since 9/11, or taking off our shoes since Richard Reid, has not made us any safer. And a long-term prohibition against liquid carry-ons won't make us safer, either. It's not just that there are ways around the rules, it's that focusing on tactics is a losing proposition."
o Banning box-cutters (and other sharp devices) has made it much more difficult to bring on an _effective_ weapon on board a plane. Nobody is denying that you can still fashion a shiv, of some kind - but the amount of damage you can do with a roughly fashioned hand weapon, versus something designed to kill lots of people at close range, is enough to deter people from trying to do so. Note - one of the principal reasons for banning box cutters and their like is so that the _other_ passengers on the plane have a pretty straightforward mechanism for subduing a malevolent passenger.
o Banning Large amounts of liquids, in the face of Liquid Bombs being _actually designed_ just makes good sense. Likewise banning powdered substances (PETN) from being brought onto planes makes sense now that we know that there are active attempts to use this vector.
Focusing on tactics is actually a very effective proposition - It's actually pretty damn difficult to bring down a plane these days from inside - not impossible, I'm sure there are a lot of vectors still left, but they are getting pretty few and far between. Not to say you don't still try and stop attacks at their source, but, if one gets by - you hope that further lines of defense will stop them.
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?
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.
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.
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...
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.
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.
It doesn't make sense. You send the worst people possible that have a chance of pulling it off.
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.
Paradoxically, the best terrorist strategy (as long as they have enough volunteers) under unpredictable screening may be to prepare a cadre of suicide bombers for the least rigorous screening to which they might be subjected, and not, as the strategy assumes, for the most rigorous. Sent on their way, each will either succeed at destroying a plane or be caught, but either outcome serves the terrorists' objective. ...
We might reflexively assume that any passenger screening system needs to be 100% effective at detecting all possible weapons and dangerous objects, an obviously difficult task. But, fortunately, that's not the requirement. Instead, the mechanisms need only be highly effective at detecting objects that can create actual terror under the conditions they will be subjected to in an actual flight. That is, in order to have meaningful security screening, we first must understand what it realistically takes to bring down an airplane. The security system can then be designed specifically to eliminate the preconditions for successful terrorism.
The TSA's much maligned "three ounce" liquid rule is, in fact, a nice example of good security engineering of this kind. ...
If that weren't the case, the TSA would have simply banned all liquids.
By all indications, the 9/11 bombers were very high on the AQ food chain. The underpants bomber didn't get tens or hundreds of thousands of dollars wired to him before the op; he was a shmuck, in a strategy designed to weaponize schmucks.
If a TSA measure doubles the manpower required to carry off an AQ op, it is almost prima facie "effective". Is, I think, the logic you'd deploy against the "combine the 3oz bottles" argument.
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.
- Shutting down commercial flight is better outcome (for the defender) than the the destruction of 9/11 - There are alternative responses, such as heightened screening, tighter in-flight security, or checking passenger lists for people with known connections to the terrorist caught.
"Well, if you succeed, you may shock the world and rally the Muslim nations to our cause, while drawing the Great Satan into an unwinnable war costing over a trillion dollars. If you fail... well, you're going to cause a lot of air travellers to be a little annoyed for five minutes."
There is this idea that terrorists are like devils, delighting in causing misfortune of any kind. I don't think that's the case. Al-Qaeda has concrete goals, like advancing Wahabbi ideology or ejecting the USA from the holy places. Failed missions don't support that, do they?
In Afghanistan, al-Qaeda is bleeding the USA of billions of dollars every month. But the article suggests that merely inconveniencing air travellers -- to the tune of maybe a few hundred million a year, widely dispersed -- might rank as an acceptable second best to a terrorist.
But is it not also possible that the TSA is purposefully putting on the guise of an incompetent governmental entity? That would seem like an excellent strategy to take, as it follows the principles in Sun Tzu's Art of War to the letter. If you are strong, appear weak, if you are weak, appear strong, etc.
If these terrorists think they can easily game the system, it will likely lead them to be less cautious, exactly as stated in the article:
Paradoxically, the best terrorist strategy (as long as they have enough volunteers) under unpredictable screening may be to prepare a cadre of suicide bombers for the least rigorous screening to which they might be subjected, and not, as the strategy assumes, for the most rigorous.
That seems like a good thing to me, and if this is the TSA's actual strategy, it's a smart one. Say one thing publicly, but do another privately.
It's extremely unlikely. For one thing, appearing incompetent in order to encourage the incautious, freelancers, amateurs and copycats is essentially using the public as bait - if you happen to miss one, people die. As a strategy it's morally and probably legally questionable.
Kirk: Mr. Spock, how many ways are there to die on this planet?
Spock: 3 Captain
Kirk: Very good, let's bring 3 guys in red shirts down to the planet with us.
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 with the number of people involved in your attack.
Your average Muslim individual would have little chance convincing a screener they were an observant Jew, and would always fail regardless of how many times they attempted.
By the time they had learned a patter that would get them through security, they would probably be bright enough to say "Hey, why am I wasting my life by blowing myself up? I should probably _run_ operations instead of being in them"
The supposed success of El Al isn't (in my opinion) that they can stop a broad community of attackers, rather it is that they are effective in profiling quickly, and passing through 95% of the passengers quickly, and only subjecting 5% to selective screening.
I'd be interesting in hearing of the experiences of any Palestinian or Muslim passengers that have flyed on El Al for anecdotal confirmation of this.
Attackers must evade the defenses just once.