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.'"

Comments

The next generation...

[John Hasler]

...will automatically detect suspicious areas of the image and rescan them slowly at high power.

Or they'll just go to transmission x-ray scanners concealed in the metal detector frame.

Re:The next generation...

[MoonBuggy]

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.

Re:The next generation...

[jfengel]

the TSA has been unsuccessful in preventing the (very few) attempted bombings in the recent past yet the attacks still failed.

Arguably, the failures were caused by the fact that they had to go to such great lengths to conceal the explosives. If they had brought on a nice, simple stick of dynamite, they'd almost certainly have succeeded.

You don't actually have to prevent 100% of attacks for security to be useful. A few foiled attacks are extremely handy in providing information and causing your opponents to waste time and energy. But when an attack is partially successful, you do need to increase security to some degree to foil a repetition.

It may not perfectly foil repetitions, but forces your opponents to change tactics, and that doesn't happen instantaneously.

It's not enough to posit that there's something both less intrusive and more effective. You have to actually show such a thing. I don't know if backscatter is optimal for the purpose, but I know it's more effective than taking no action.

And in related development

[hey!]

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.

Milimeter wave RF scanners too?

[hawguy]

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)

Re:It's theater...

[adolf]

And if you actually try it instead of just thinking about it, you'll find that both broken (cracked) and scratched records can behave very similarly upon playback.

I've been around long enough that I've tried both.

So, in the interest of pedantry, I'd like to say that while your new word usement does seem to be valid, its validation does not seem to in any way invalidate the validity of the previously-valid phrase.

Please feel free to use both terms interchangeably in such contexts as this, for they are synonymous.

Thanks!

Re:Solution

[speculatrix]

the TSA have already forced a woman with a prosthetic breast to subject herself to intrusive scrutiny: http://www.cbsnews.com/stories/2010/11/19/national/main7070415.shtml

so, no doubt the TSA staff will soon be equipped with endoscopes and be trained in keyhole surgery to prevent terrorists implanting bombs inside their bodies.