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Backscatter X-Ray Machines Easily Fooled
Pinckney writes "A paper by Leon Kaufman and Joseph W. Carlson in the Journal of Transportation Security asserts that x-ray backscatter machines are not very effective (PDF) even in their intended role. While carelessly placed contraband will be detected, the machines have glaring blind-spots and have difficulty distinguishing explosives from human tissue. As they write, 'It is very likely that a large (15–20 cm in diameter), irregularly-shaped, cm-thick pancake [of PETN explosive] with beveled edges, taped to the abdomen, would be invisible to this technology. ... It is also easy to see that an object such as a wire or a boxcutter blade, taped to the side of the body, or even a small gun in the same location, will be invisible.'"
This obviously means that we are going to need better technology. We'll need technology that will be able to give us a full color representation of your completely nude body, but only if you're a hot chick. - Your Friendly local TSA Agent
Passengers and cargo are a security risk. Prohibit them from boarding planes, and everyone will be safe.
(Pilots are also a security risk. In the future all planes will fly autonomously, controlled by AIs.)
(Programmers writing the AIs are also a security risk. You know what? Scrap those planes, they're not carrying anything anyway.)
the former head of Homeland Security, Michael Chertoff helped sell them to the government and the government mandated them and removed everyone's rights.
American anthem playing in background.
It's highly questionable whether the machines are even capable of identifying "suspicious areas of the image." But suppose for a moment that they are. These scanners are already, in themselves, more of a safety hazard than actually flying. They have been through nowhere near the degree of rigorous safety testing and analysis that any component of an aircraft has to go through. While exposure to the intended dose of radiation for a scan may be safe (even that is debatable), the scanning process is software controlled. Imagine if the software crashes in the middle of a scan, or the scanner mechanism sticks.
And now, suppose that it is possible to detect suspicious areas of an image and do a more thorough scan. This simply increases the safety risks of these machines. X-ray scanners? How is that exposure going to be controlled? Is testing ever going to be held to the degree of rigor required for aircraft? If not, why should we be willing to accept the risks of using these machines?
The fact is that if we really care about people taping explosives to their stomachs, the only way to detect this is with a thorough search (a.k.a. "enhanced patdown"). If we are really that concerned about security, that is what every traveler should be subject to. And if we aren't comfortable with searching passengers like that, then we really ought to stop being such cowards and accept the quite minimal risk that someone is going to get one of these Rube Goldberg explosive devices past security and actually succeed in harming an aircraft with it (unlike the shoe-bomber and underwear bomber attempts, which did not harm either aircraft).
Not to sound like a broken record (does that phase mean anything to people or did I just show my age), but I'm not sure why this surprises anyone. It's not about security. It's about security theater. And until the TSA fundamentally changes the way they do things, it always will be.
--- What parts of "shall make no law", "shall not be infringed", and "shall not be violated" don't you understand?
Why didn't the TSA test this technology first to make sure it works? I mean, it's not like cloth tape and a flattened explosive are unprecedented or amazingly cunning bits of circumvention! Why not hire 20 nerds and give them a week to figure out if they can sneak something truly dangerous through the scanner? As long as they can do so reliably, wait for the next version of the machine and test again. Only when it works should you place the order!
Thing is, we don't even really need "a better way of detecting terrorists". The incidence of terrorism against airlines is practically a rounding error and as we've seen, the TSA has been unsuccessful in preventing the (very few) attempted bombings in the recent past yet the attacks still failed. If we removed the theatre and replaced it with nothing, maybe keeping a few basic and effective measures to discourage obvious attacks, we'd be better off, and the risk would still be negligible. If we replaced it with something actually effective then that'd theoretically be even better, but most effective methods are expensive, invasive or both and I'm unconvinced that they would be worthwhile considering how low the risk is.
The Boston Globe reported today that a the mutilated body of a teen boy found last month in a Boston suburb probably fell out of the wheel well of an airplane he is believed to stowed away on. Several articles of his clothing were found scattered along the flight's approach to Boston's Logan Airport.
Earlier this year in Japan a body was discovered in the wheel well of a flight originating at New York's JFK. Investigation later revealed that the unfortunate hadn't stowed away in New York, but in Lagos Nigeria *two months earlier*.
What does this tell you about all this body scanning hoopla? We're building a fortress that sports a fearsome looking portcullis but has open windows on the ground floor.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Does this same condition exist for the Millimeter Wave RF scanners too, or do they have better resolution or discrimination abilities?
I haven't traveled much since these scanners went into effect, but so far I've only seen the RF scanners.
Last time I encountered one I asked the TSA rep if it was RF or X-ray, and she said "It's millimeter wave, and it's the same as an ultrasound". I told her that that can't be true since an ultrasound doesn't use RF energy, and she said "It *is* the same, now move along". I reported her misinformation to a supervisor, but I'm not sure he even understood the difference between ultrasound and an RF scanner.
I'm fine with the RF scanners (I don't think they are all that effective since a determined terrorist will use one of the many holes in airport security to bring in his weapon -- plus my "junk" isn't all that interesting), but I don't like being lied too (or worse someone directing me into a device that she doesn't even have a basic understanding of -- surely the difference between sound and RF energy is not too hard for a TSA agent to understand)
Precisely. The shoe bomber got through, and his bomb didn't work. Ditto the underpants bomber. Airport security failed miserably. It didn't matter.
As for the liquid bombers, it's still debatable whether their bomb would have worked, but who cares? They never even made it as far as the airport!
I am still waiting for the TSA to present the American people with any evidence -- even the tiniest shred of evidence -- that they have ever once in their entire history caught an actual terrorist.
Maybe these devices and this system isn't perfect, but it's better than the alternative, which is doing nothing.
Callous as it may sound, we balance convenience and cost against people's lives every day. Reducing the national speed limit to 10MPH would undoubtedly save lives, but people's need to travel is deemed to outweigh that benefit.
Having accepted that we as a society do allow some increased risk in exchange for our day-to-day rights, profits and convenience, the question becomes: "How does the potential for an attack balance against the cost and restriction presented by the security measures?"
A measure such as this is very expensive, only moderately effective, potentially risky (I haven't had a chance to read up properly on the radiation issues) and felt by many to be an unacceptable invasion of privacy. The risk presented by terrorists is minuscule (look at all the juicy unsecured targets in the US that simply aren't being attacked, then compare that to Northern Ireland - the latter is what you see if there are actually a reasonably sized core of determined attackers). To me, this seems like an unacceptable trade-off.
Yup, experts have been warning about this all year. Meanwhile, explosives detectors (you know, the ones removed from airports last year because they were too much trouble to maintain) seems to be a banned topic in the news.
Meanwhile, we're letting utterly unchecked luggage onto the plane.
Don't worry, we've solved that by banning wifi. Luckily, there's no other way besides wifi and by hand to detonate explosives.
Unfortunately the TSA now has too much invested to suddenly admit it probably wasn't a good idea to stop using the more effective machines that are less invasive (they were the round swabs on luggage) replaced with the less effective machines that are more invasive.
The TSA doesn't have to 'admit' things regardless.
As I've suggested, the TSA should be required to operate something like this:
There is an independent office outside the whole TSA, operated by non-TSA people. Let us all it the TSA Inspector General office.
You show up there and present some object to wish to smuggle past TSA, or take one from them. It doesn't have to be the actual banned object, but it has to be one that would 'serve the function' of the object.
They write down your name and what you're doing. You give them a $100 bond.
If you manage to get that item past TSA, you then got to the IG office on the other side, and explain how you did it, and they pay you $1000 out of TSA's budget. The TSA is not allowed to know your name or any other identifying information so they can't start searching you extra. (The IG's office, OTOH, will know your name and the plane you're going to, and you won't be let on the plane, and be in rather a lot of trouble if you don't show up at their office with the stuff.)
If you don't get it past TSA, you forfeit the bond.
REPEAT.
The very first thing people will do is smuggle 'razor blades'. By the thousands. Easy easy money-making scheme. There's all sorts of ways to hide very sharp things.
At some point, the TSA will stop banning stuff they can't possibly stop. Or go broke. Or actually get to the point where only naked people get through.
Let's call it 'privatized security testing'.
If corporations are people, aren't stockholders guilty of slavery?
>not very effective (PDF) even in their intended role
You're implicitly buying in to the claim that their intended role has something to do with safety.
The purpose of a system is what it does. The ~$200,000 scanner purchases funnel tax money to a company which made payments to the former director of Homeland Security. They condition people to being treated like prisoners. The first was deliberate.
They're working perfectly.
Most people don't realize that backscatter is an imaging tool and not a bomb detector. It requires a human operator to interpret the image. If the bomb is well blended into body contours, there is a high probability that the operator would miss it. If you look at the backscatter sales literature (it's on their web sites) it shows images of people with concealed knives or guns. Stuff that would also set off a metal detector.
In my opinion, it is a little disingenuous that the TSA is using the bomb threat as the justification to switch from metal detectors to backscatter. One of the reasons that the shoe and underwear bombers failed is they weren't able to conceal a proper detonator (which contains metal), and resorted to trying jerry rig a lighted fuze detonator. So in that sense, the metal detectors did do their job. But if concealed explosives were the primary threat, then x-ray in tandem with bomb sniffing dogs or some type of actual bomb detector would be more effective. The other downside to imaging is the human operator spends hours looking at thousands of passengers. There is a good chance that the operator won't be alert enough to spot a bomb or weapon, even when it is not perfectly concealed.
As I have said, the only way to be absolutely sure is to perform a premortem autopsy on every passenger. The downside is that somewhere along the way, it becomes a postmortem autopsy. The good news is that airlines could then stack passengers into cargo planes at twenty time the density as current passenger planes. The bad news, no more round trip tickets.
"These scanners are already, in themselves, more of a safety hazard than actually flying. They have been through nowhere near the degree of rigorous safety testing and analysis that any component of an aircraft has to go through."
Consider the level of testing and analysis that the *very same device* would require if it were labeled "medical equipment" rather than "airport security equipment". Consider also the site and personnel licensing required to operate one (probably akin to that required for a modern xray machine).
~REZ~ #43301. Who'd fake being me anyway?
That depends on if the passenger had Taco Hell the previous night.
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NOW you're thinking like a TSA administrator!
A security measure that is not perfect can still be good. Okay it can be circumvented by a limited set of actions.
A terrorist attack also doesn't have to be perfect to be good. Neither the shoe, underwear, nor toner-cartridge bombs went off and they still cost $billions. Unfortunately, the long-term economics of this don't favor us.
There's a perfect xkcd for my sig but I'm too lazy to look it up. sudo someone go find it.
You might have gone through radiotherapy, but these machines work on different frequencies and different energy levels. Yes, the wave energies might not be as high as in radiotherapy, but that doesn't make it less dangerous, it actually means that the skin gets the dosage instead of the body.
The dosage you have received over the course of your treatment was carefully measured and calibrated often. It was also administered by a person trained in radiography and the repercussions of radiation.
Also, remember that the dose applied in the scan is done over a relatively short period. For the sake of an analogy, think of the difference in pressure between a stilletto heel and a boot heel on your foot. One will hurt, the other will go right through you.
Compare the mass of your skin to that of your body, add in that you're getting a dose like that in a short time and then come back to me when you realise that it is actually a very serious health concern.
Yes, IANaRP (nuclear and radiation physicist). Posted anon, because I'd like to keep my job.
Behavioral profiling, such as what is practiced by the Israelis, is both cheaper and more effective than searching for weapons. If we adopted behavioral profiling, screened all baggage for explosives and ran passengers through the air-puff chemical sensors we'd have a system that protects travelers privacy much better, is much more effective and significantly cheaper than our current system.
Explosives are the real threat anymore. A few terrorists wonldn't be able to take over an airplane, not now that the passengers will fight back and the cockpit doors are reinforced. Preventing passengers from bringing things like nail clippers is just asinine.