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Fast, Accurate Detection of Explosives
It doesn't come easy writes "Fast, highly reliable detection of residues that could indicate the presence of explosives and other hazardous materials inside luggage is now possible with technology under development at Purdue University. Recent improvements to a previously developed prototype have proven successful at detecting at the picogram (trillionths of a gram) level in lab tests, about 1,000 times less material than previously required. From the article: 'In the amount of time it requires to take a breath, this technology can sniff the surface of a piece of luggage and determine whether a hazardous substance is likely to be inside, based on residual chemicals brushed from the hand of someone loading the suitcase.'"
Ok, here's something I've always wondered about. If you have these exquisitly sensitive machines that can detect even a few molecules of material, aren't they by the same token super-vulnerable to being attacked by "chaffing" or overloading?
Couldn't a bad guy simple walk around the airport with some material on his shoes and permanently, for all time, destroy the effectiveness of the instruments? I mean, how could one possibly clean a whole airport down to a few molecules worth of the stuff?
Isn't that a *huge* hole in any "super sensitive" chemical detection system?
now, when I fly, I have to worry not just about whether I handled matches or toy cap guns or went to the shooting range in the last 24 hours, but also whether my neighbor, my dog, or the taxi driver handled any nitrate-laden deli meat in the last month.
Good luck to explosives manufacturers - there go your chances of ever flying again!
DROS - Open-Source Robot Software
This is certain, just like the current TSA baggage screening, to be used to justify unlawful searches for drugs and other contraband. In fact, just like those baggage searches, this will undoubtedly become the #1 use of this technology, in fact I would bet good money that it is part of the intent of the people funding the development of this stuff. Just wait and see.
People fly because they want to go somewhere as fast as possible. With recent rules and regulations regarding airports, it's been becoming slower and slower to fly anywhere. Perhaps with the advancement in technology such as this, we can slowly relieve the stress of having to fly somewhere.
$fortune
Tomorrow has been canceled due to lack of interest.
Expect every airport to be shut down for a week after the 4th of July.
Fire. In all my experience as a pyromaniac, it has quickly and with 99.99% accuracy told me whether or not a substance was flammable.
Yes, it's vulnerable to false positives -- for example, some construction workers are going to have to go through the slow way every time they fly.
That's okay, though -- the positive thing here is that the initial check can be made much much faster. Most luggage and most people can just be zipped through (they'll hardly need to stop walking!)... which leaves more resources available to help the inevitable false positives get processed in the old, slow way (with the little explosive-check tabs, or a search by hand) as efficiently as possible.
That's what matters, isn't it? Speeding the whole thing up, to make a reliable screening feasible.
Well, if it was used sensibly, that would be ok.
The risks are still two fold:
1) If the rate of false positives is low, alot of people will get through quickly. However, if you are one of the false positives, you may well get a very bad deal at the airport. Having been singled out on one trip to the US for no apparent reason (Probably because I took a "one way" flight so maybe they thought I was not planning to return!) I can assure you its no fun if you end up on the wrong end of a statistical test.
2) If there are too many false positives, people get blase. After all, how many people in the history of all plane flight have put explosives on a plane? A few dozen maybe, probably less than 100 all up. But any test will likely have many more false positives, and this will mean that these people get ignored.
3) You may still be using the wrong test, and get falsely reassured. After all, the September 11 hijackers would have passed a chemical detection test, so they would have been fine to board, no? Again, the real problem here wasn't that the test systems failed, it was the human management of the system - people weren't serious enough about the tests that were already in place.
So, you end up putting alot of money into doing something that will help very few flights, incovenience a large total number of innocent people, and possibly not protect the public at all.
After all, 3000 people died on September 11 due to a rare incident that is unlikely to ever happen again. 3000 people die every day in road accidents around the world. Which do you think gets society the best return for its time and energy? Yes, we have to stop terrorists, but just how far is it worth going here?
Michael
There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
"More people rode the CTA today than will pass through O'hare and Midway over the entire Thanksgiving weekend. Yet the feds only provide a penny per passenger for security on buses or trains... compared to seven or eight bucks for each plane passenger."
Doesn't really make sense, does it?
End transmission.
Regarding the article, nanogram sensitivity (a trillion molecules of TNT) is utterly unimpressive. The vapor pressure of most explosives is so low that you need femtogram sensitivity to directly sense vapor. For an explosive like RDX that has an absurdly low vapor pressure, you really want attogram sensitivity (about a million molecules). You can heat up dust and surfaces to vaporize more explosive, but with a mass spectrometer you then run into a problem with selectivity: many ordinary boring compounds will have the same molecular weight as the explosive--the signal will be swamped by the noise. (Hmmm ... the article says they're using clever ionization, and tandem spectrometry. That helps a lot, but they still have a hell of a problem to solve.)
The article says "'If you tried to detect a particular compound out of a mixture of thousands of different substances, you might begin to see the limitations of this method,' Talaty said. 'But real-world explosives are not that complex.'" What, people walk through airports with purified blocks of luggage? No! You get a suitcase drenched with sweat (which includes urea), solvents, ammonium nitrate from natural sources, perfumes, plasticizers, plastic monomers and short chain polymers, various mineral oils, a whole boat-load of volatiles from living things, and many more. The background signal is a freaking nightmare. I work in the explosive detection field, and I sure wish it was as easy as they say.
It seems to me that you could certainly circumvent this easily enough, with just some social engineering. Carry a lot of sniffer-activating things in your luggage. Travel 15 times on the route, or until you reliably know the security people.
After 15 times, the conversation goes like so:
You: "Hi Steve."
Security: "Hi John."
Detector : beeep! bip! beep! bip! beep! BEEEEEEEP!
You: "Damn detector. Can't they tone those things down a little?"
Security: "Every time you go through, these things go off."
(opens luggage)
Security: "Cheese, fertiliser, and trinitite. Again."
You: "Well, a man's got to earn a living some way. Isn't there some form or something I can fill out to get out of this?"
Security: "Nope. Everyone gets checked."
(closes luggage)
Security: "Off you go."
Travel 15 times without the bomb so everyone gets to know you.
The 16th time, travel with the bomb concealed somewhere in your luggage, but
leave the cheese , fertiliser and trinitite on top. Odds are pretty good that you'll get on that plane.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
"You'd hope the screeners would wonder why they suddenly started getting a 100% hit rate and figure it out."
You're overestimating the intuition possessed by law enforcement and security people.
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