TSA Turns to Full-Body Air Passenger Scans

Updated: The Transportation Security Administration is rolling out full-body image scans as an alternative to pat-downs for air passengers.

With a large majority of passengers opting for full-body imaging scans over a traditional pat-down in secondary airport screening, the Transportation Security Administration has announced it will roll out an installation of millimeter-wave imaging in Phoenix and will also test backscatter imaging in New Yorks John F. Kennedy International Airport and the Los Angeles International Airport.

The TSA announced Oct. 11 that 79 percent of the public prefers full-body imaging technology over pat-downs. Millimeter-wave imaging is a very fast scanning technology that takes 2 to 4 seconds to create a three-dimensional holographic image that airport screeners can spin around in order to search an entire person.

Millimeter-wave is similar to backscatter imaging in that they are both full-body scanning technologies, but millimeter-wave doesnt render the same type of startlingly frank images that have long been associated with backscatter.

Backscatter X-rays in their earliest renditions produced images of photo quality that were disturbingly frank—EPIC (Electronic Privacy Information Center), which has called the images a "virtual striptease," has an image on its site of Susan Hallowell, director of the TSAs research lab, that gives an idea of how much detail was rendered in an original backscatter system. Even that explicit image was distorted so as to blur the private parts, and the TSA replaced those photo images with cartoonish outlines in a trial backscatter system in Phoenix.

Backscatter has since improved on the privacy front, however. The photo posted on EPICs site is actually from a 2003 generation of American Science and Engineerings SmartCheck System and lacks a privacy algorithm that AS&E has been working out with TSA for over two years, Betsey Rogers, a spokeswoman for the leading backscatter X-ray technology provider, told eWEEK. As a matter of fact, the 79 percent of air passengers who opted for full-body scans over pat-downs were actually opting for backscatter scans. "The TSA identifies the capability to detect explosives at the passenger checkpoint as one the greatest security vulnerabilities facing aviation today. Backscatter with privacy protection mitigates that risk and has proven that it is publicly acceptable," Rogers said.


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The TSA, aware of lingering privacy concerns concerning backscatter, stressed in its announcement that the millimeter-wave images produced in the Phoenix airports new installation will be anonymized and protected from prying eyes. "We are committed to testing technologies that improve security while protecting passenger privacy," said TSA Administrator Kip Hawley in a release. "Privacy is ensured through the anonymity of the image: It will never be stored, transmitted or printed, and it will be deleted immediately once viewed."

Millimeter-wave also has the added bonus of being nonradiating, relying as it does on harmless electromagnetic waves to generate an image based on energy reflected from a body, as opposed to X-rays. The TSA claims that the energy emitted by millimeter-wave is 10,000 times less than that of a cell phone.

The TSA plans to test millimeter-wave passenger imaging at the Phoenix Sky Harbor Airport as a voluntary alternative to a pat-down during secondary screening. The technology uses algorithms to automatically detect anomalies—for example, images that represent objects outside of the body. Both it and backscatter detect not just metallic objects but any object, which is necessary for detecting weapons such as ceramic knives.

The procedure will involve being led by a security staffer into a boothlike machine and remaining still for a few seconds, in two different positions. Using two antennae that simultaneously rotate around the body, the booth will create a 3-D image of a traveler. At the completion of the scan, the passenger steps through the opposite side of the millimeter-wave portal.

The TSA said that privacy will be ensured by having screeners view images remotely. "From this location, the security officer cannot ascertain the identity of the passenger, either visually or otherwise, but can communicate with a fellow officer at the checkpoint if the passenger presents a potential threat," the agency said in its release. "A security algorithm will be applied to the image to mask the face of each passenger, further protecting privacy."

The TSA plans to also test backscatter machines at JFK and LAX in coming months and will purchase eight portals costing $1.7 million each to be used in additional pilot programs.

Millimeter-wave is currently being used or tested internationally at sites that include the United Kingdom, Netherlands, Japan and Thailand.

Editors Note: This story was updated to correct outdated information about backscatter technology and to correct misstatements about which full-body imaging technology is being deployed where. eWEEK regrets the errors.

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