Is This a Good Idea? Full-Body Scans at Airports?

May 29, 2009

A lot of the time, I blog in this space about speculative inventions and applications of technology, such as bacteria-sized medical robots or transoceanic underwater maglev trains. This week, however, we’re going to look at a controversial technology that is already here: active millimeter-wave full-body imaging, which penetrates clothing to reveal anything concealed beneath the fabric, from hidden objects to the human body itself. The federal Transportation Security Administration already is using such scanners at 19 airports across the nation to thwart terrorists trying to sneak bombs or weapons through security checkpoints.

Keep reading! There's more...

TSA reportedly had been planning for years to deploy the scanners as a backup option for passengers chosen for secondary inspections. But as the New York Times recently reported TSA officials are so happy with the scanners’ performance at the 19 pilot sites that they now intend to use such imaging to replace walk-through metal detectors that for years have been the primary line of defense at airports. They’re planning to install more of them across the nation.

Proponents say that the scanners have a lot of pluses. The devices will spot nonmetallic objects and liquids that metal detectors might miss, they say, and they’ll also largely eliminate the need for pat-down searches for airline passengers with joint replacements, prosthetics and other medical devices that can set off metal detectors. TSA claims that such passengers can be scanned in just 15 seconds, as opposed to the two to four minutes it would take to search them by hand.

For the privacy conscious, critics point to one glaring downside: Security officials will get a chance to see what you look like naked, and though TSA has said that it will delete your au naturel image immediately after use, the agency’s screeners already have a track record of being somewhat less than trustworthy. Additionally, with the results of TSA’s evaluation of the technology shrouded in secrecy, there’s another nagging issue: How well does scanning really work? Are there potential countermeasures that a terrorist might employ to defeat the scanner and smuggle a bomb or weapon onto a plane? At least one scientist seems to think there are such risks.

When I first heard about the scanners, I pictured something like the creepy “ no unauthorized weapons beyond this point” full-body x-ray screen that Arnold Schwarzenegger walks through in the 1990 sci-fi movie Total Recall. But actually, the images look more like this. Basically, the two antennas rotate around the body, projecting beams of radio-frequency energy in the millimeter-wave spectrum over the body’s surface at high speed. The energy reflected back from the body — or objects on it — is used to construct a three-dimensional image, which is then displayed on a remote monitor. (TSA says the facial features are blurred as an additional privacy measure.)

As an official from L-3 Communications, the maker of TSA’s scanners, explained in 2007:

L-3's millimeter wave technology pinpoints objects made of any material, including liquids, rubber, wire, plastic, and metal, to quickly and easily locate weapons, contraband, and other threats concealed under an individual's clothing. The portals detect concealed and hidden objects such as metallic and non-metallic weapons and virtually all known explosives, and other contraband in seconds.

Here’s a cheery video from TSA explaining the scanning process:

TSA’s official blog is even more blithely reassuring:

Millimeter wave will allow our TSOs to view a noninvasive image of a passenger revealing any items that were not divested. These images are friendly enough to post in a preschool. Heck, it could even make the cover of Reader’s Digest and not offend anybody.

Not everybody is satisfied with that disclaimer. The Electronic Privacy Information Center, a watchdog group, derides the technology as a “virtual strip search.” EPIC is gathering signatures on a petition letter to Homeland Security Secretary Janet Napolitano, which demands that the program be suspended.

In addition, U.S. Rep. Jason Chaffetz, a Republican from Utah, has introduced legislation that would ban the scanners at airport. From his D.C. office, where the freshman legislator saves money by sleeping on a cot when Congress is in session, Chaffetz recorded a YouTube video in which he explains his privacy worries.

It strikes me that when even a conservative Republican like Chaffetz is worked up about the civil liberties implications of a new technology, it’s time to pay attention.

Additionally, I have another question about the scanning technology. How impervious is it to hacking or countermeasures? TSA (whose press office didn’t return my phone message) isn’t revealing the results of its evaluation, and the available scientific literature on millimeter-wave imaging that I found on the Internet doesn’t yield any answers, either. But I did find this lone caveat, buried in a June 2008 USA Today article on the scanners:

The scanners do a good job seeing under clothing but cannot see through plastic or rubber materials that resemble skin, said Peter Siegel, a senior scientist at the California Institute of Technology. "You probably could find very common materials that you could wrap around you that would effectively obscure things," Siegel said.

I emailed Siegel in an effort to get him to elaborate on this, but he answered back:

Probably best if I say no more on this, considering the application.

That may not help. Security expert, author and blogger Bruce Schneier, the chief technology security officer for global telecom-Internet giant BT, suspects that if such a vulnerability exists, terrorists already have figured it out. But in a phone interview, Schneier raised an even more provocative question. Even if we install the absolute primo, state-of-the-art scanning technology at airports and prevent weapons and bombs from being hidden in clothing, won’t terrorists simply adopt new tactics or shift to different targets?

“Defending against tactics and targets makes sense only if there are a few of each,” he contends. “The reality is that there are 10 million targets in this country, and just as many ways to attack them. We put scanners in airports because terrorists attacked airplanes last time. We’re screening for liquids because terrorists used liquid explosives in the past, not because they’re more effective than solids, which they aren’t. We take off our shoes and not our underwear because that’s where Richard Reid hid explosives, not because shoes are better. We take away guns and bombs, and they use box cutters. We take that away, and they’ll use something else. This is a stupid game, and we should stop playing it.”

Schneier argues that the only really effective way to prevent terror attacks is to be proactive. “Intelligence, investigation, preemption — they work, no matter what the target or tactics,” he says. Schneier points to the FBI’s and the New York City police department’s recent preemption of an alleged plot by four suspects to attack two Bronx synagogues and shoot down a military aircraft, which was cracked by conventional detective work plus the targeted use of video and audio surveillance.

So what do you think? Are full-body scans at airports a good tool for preventing terror attacks? Or does the whole thing sound too problematic — or embarrassing — to you? Express your opinion below.

Comments

[Patrick Kiger]

An important update: TSA spokesman Jon Allen now says that contrary to the NY Times report (which quoted a TSA official as the source), TSA isn't making the switch just yet. “We’re still piloting the technology, with 40 machines at 19 airports,” he told me in an interview. “There’s been no decision to replace the metal detectors.” But I'm still wondering if the agency actually changed its plans after the brouhaha stimulated by the Times article.

Also, I talked to EPIC's associate director, Lillie Coney. “You still can’t get away from the issue that you’re gathering personally identifiable information," she warns. “They say right now that the policy is that they won’t collect it, but that policy can change. The potential exists to abuse this technology.”

[Patrick Kiger]

ANOTHER UPDATE: I also spoke to an MIT scientist, Paul Woskov, who works with millimeter waves in energy research. While generally favoring TSA’s use of the scanners as part of an array of security measures, he warns that there may another way to get around them. Just as millimeter waves won’t penetrate skin, they can’t go through wet cloth, either. So in theory, a terrorist might be able to wrap a weapon in moist cloth and wear it against his body under his clothes, and pass through without detection. “You could make it see something that looks like the body’s moisture content, but is not,” he says.
I asked TSA about this and other potential vulnerabilities in an email, but I'm still waiting for the agency's response, which I'll post as soon as I get it.

[Astroboy]

Id like to be there when Megan Fox goes through the scanner!

[Caffeine Driven Stress Magnet]

These scanners really give me the creeps. I don't want anybody to see my stretch marks!

[Natural Man]

This is an invasion of privacy and totally unnecessary.

[Ken Caldwell]

I agree.

[Neo-Luddite]

No matter what sort of sophisticated technology they install in airports, terrorists will find some way to get around it if they really want to.

[Patriot]

Privacy isn't going to do you any good if a terrorist sneaks a bomb or a gun onto your airplane.

[Liberal Tina]

I would refer you to Bruce Schneier's take on that.

[Mark Lowe]

how much is the use of these scanners going to slow down the process of getting on an airplane?

[Patrick Kiger]

I'm surprised...I figured I'd get more comments on this one.

A TSA official told the NYT that the scans didn't slow down the lines that much.

{{Mr. Kane said that the machines, in tests, have moved people through at about the same rate as the metal detectors.

“It’s very, very quick; the scan is about two seconds,” said Sterling Payne, an agency spokeswoman. “They’ll tell you the position to stand in, there’s the quick scan, and then you step out of the machine and wait for the resolution, which happens in a separate room in another part of the checkpoint.” }}

[Gary Waggoner]

are these active millimeter wave scans more or less revealing than backscatter xrays? That was the technology that they were looking at a few years ago.

[Patrick Kiger]

Good question, Gary. I would say that the backscatter x-ray scanners are more revealing.
http://images.google.com/images?hl=en&q=backscatter+x-ray+images&um=1&ie=UTF-8&ei=VGYkSse1NIbAMt7rmIsF&sa=X&oi=image_result_group&resnum=1&ct=title

[Cindy Benson]

No matter how sophisticated, this scanning system is still vulnerable to human error, because it's a person who has to spot the weapon or bomb in the image.

[Mothra]

PJK: Did the TSA ever respond to your questions?

[Patrick Kiger]

I still haven't heard back from TSA. Here's the email that I sent them.

----- Original Message -----
From: Patrick J. Kiger
To: jon.allen@dhs.gov
Sent: Tuesday, May 26, 2009 4:25 PM
Subject: the questions

Jon:

I'm the Science Channel blogger (http://blogs.discovery.com/good_idea/) who contacted TSA last week. As you requested, here are some written questions regarding the use of active millimeter wave scanners in airports.

1. In our phone conversation last week, you told me that TSA is not planning at this time to replace metal detectors with scanners at airports, contrary to what the NY Times reported on April 7. (http://www.nytimes.com/2009/04/07/business/07road.html?scp=5&sq=full-body%20scans&st=cse )
However, I notice that the Times article quotes a TSA official, Robin Kane as the source. Was he not quoted accurately, or did he misspeak?

>

2. Would you tell me more about the pilot program? Is the purpose of the program to test the public's reaction to the scanners, or to test their effectiveness at detecting weapons and other dangerous items in actual use?

3. How much and what sort of testing has been done to evaluate the scanners' effectiveness at detecting weapons and other dangerous items? How well do the scanners perform, compared to metal detectors and other systems already in use?

4. As the scanners have been described in media accounts, a TSA employee in an adjacent room monitors the images visually on a screen in another room. Is that the extent of the monitoring, or is there also an automated component, such as a visual or aural alarm to alert the employee that the scanner has detected an object?

5. According to news reports, the scanned images are immediately deleted after visual inspection by the TSA employee. Since there is no record of the scans to examine, how will TSA audit the system for effectiveness? In the event that a weapon or other dangerous item slips through the checkpoint, how would TSA determine whether human or machine error was the cause?

6. I spoke to a scientist at a major research university who has worked extensively with millimeter waves. He told me that the airport scanners have potential vulnerabilities. For example, he said that a weapon or other object wrapped in wet fabric and concealed in clothing may might appear indistinguishable from skin. "If you have a material loaded with water vapor and you have it on like underwear, you have a space where the active system is absorbed by moisture. You could make it see something that looks like the body's moisture content, but is not." Does TSA have a response to this?

7. Peter Siegel, a CalTech scientist who was interviewed by USA Today in 2008 (http://www.usatoday.com/travel/flights/2008-06-05-bodyscan_N.htm), pointed to another possible vulnerability.
>
Does TSA have any response to this?

Regards,
Patrick J. Kiger

[RDC]

I have an idea or question that for some reason I actually wonder if its already been thought of or if its an undergoing process?

I was watching Discovery science this morning, where a company is researching on a technology that transmits brain waves to data for digital information.

I’m amazed and thrilled to see how far science has already accomplished.

But the reason for this letter is not to brag about some company’ success to hopefully sell they’re product; although it’s a very good invention and my puny brain will never reach they’re level of intelligence to invent such a amazing product for the future.

But there is where it hit me!

Imagine if the process can be reversed and data will be converted to brain waves that our brain can detect making information immanent.

Imagine processing data like a computer via frequency or who knows what sort of tool.

I’m not a genius or have any technical degree but imagine if its possible?

To become smart just by receiving data.

It might sound crazy!!!!!!

But this company did the opposite. And I know that it can be reversed.

Hek, a few decades ago we never thought technology and science would leap this far and we forget and take for granted what the past used to be.

If that company already achieved in converting brainwaves into data, how about reversing the process and make the world a bit smarter and eventually better.

My vision for this technology will benefit every one in every way.

Years of studying hard cramped up into further research.

This doesn’t mean that the average student should become lazy and only get information and become smart but find a way to balance the process and make fair for human kind to share.

We all know knowledge is power. And imagine sharing the most powerful essence on earth.

My message regarding this letter is to trigger some smart people out there to look into this information and hopefully make something out of it.

This is the key to human kind problems.

And this is no sci-fi or preposterous idea.

It would be if not looked into!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Humankind solution to all problems!?

[Astroboy]

Did you know that you can take apart a nine-volt battery and use the smaller batteries inside to replace AAA batteries in an MP3 player? I just found this on the web.

[Patrick Kiger]

I do. My nine-year-old son showed me that trick yesterday.

[Dr. Strange]

I don't get the sense that people are very worried about their privacy at airports anymore. The way we get jammed into planes these days by the airlines, privacy is zippo anyway.