How Easy Is It To Defeat The Pornoscanner?
BoingBoing's Cory Doctorow blogs Leon Kaufman and Joseph W. Carlson's "An evaluation of airport x-ray backscatter units based on image characteristics," published in the Journal of Transportation Security (fulltext PDF here). An excerpt:
It is very likely that a large (15-20 cm in diameter), irregularly-shaped, cm-thick pancake with beveled edges, taped to the abdomen, would be invisible to this technology, ironically, because of its large volume, since it is easily confused with normal anatomy. Thus, a third of a kilo of PETN, easily picked up in a competent pat down, would be missed by backscatter "high technology". Forty grams of PETN, a purportedly dangerous amount, would fit in a 1.25 mm-thick pancake of the dimensions simulated here and be virtually invisible. Packed in a compact mode, say, a 1 cm×4 cm×5 cm brick, it would be detected.The images are very sensitive to the presence of large pieces of high Z material, e. g., iron, but unless the spatial resolution is good, thin wires will be missed because of partial volume effects. It is also easy to see that an object such as a wire or a box- cutter blade, taped to the side of the body, or even a small gun in the same location, will be invisible. While there are technical means to mildly increase the conspicuity of a thick object in air, they are ineffective for thin objects such as blades when they are aligned close to the beam direction.
Quick, someone needs to tell the government about this treasonous post so that it can be taken down and no one will know how to to circumvent the scanners that are keeping us safe! Those electrons must be vaporized, and those who would expose security holes sent to Gitmo.
Christopher at December 28, 2010 9:51 AM
I can come up with about three different ways to bring an airliner down -- using nothing but the contents of the aircraft itself, maybe one or two carry-on items (passable through security), and a little bit of time and ruthlessness.
The other side -- how ruthless can the rest of the passengers be under threat. Even prior to 9/11 a passenger was killed by fellow passengers when he tried getting through the cockpit door.
But I don't even need to be on the airplane -- MIJI -- pronounced me-gee has been around for years. An example was sort of shown in Die Hard 2. If I set up a more powerful ILS transmitter within a mile of the original transmitter with the right offsets and lowered the altitude during the blizzard onset on Christmas eve -- I could have probably brought a bunch of aircraft down all over D.C. or NYC.
As I have said before -- short of the pilots doing it -- there will never be another 9/11 attack. Maybe planes will be blown out of the sky over time. But the hijackers will not get away with turning them into guided missiles.
Jim P. at December 28, 2010 8:04 PM
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