The security theory and troubling practice behind the TSA's PreCheck security lines

Life in the fast lane: So long, TSA fairy godmother

TSA Precheck security

So long, TSA fairy godmother

If you're a relatively frequent traveler, there's an occasional pleasant experience you've probably had over the past few years: as you approach the seemingly interminable security scrum, a TSA agent gently and subtly directs you in another direction. Suddenly, you're in a line that's shorter and faster than the others, and when you reach the screening area, you get to leave your shoes on and your laptop snug in your bag. What magic is this?

You just got semi-randomly selected to experience TSA PreCheck, an expedited screening process that bypasses the usual rigmarole.

TSA Precheck security

Pay to play

But why were you able to go into that line in the first place? It's for people enrolled in the TSA PreCheck program, and the reason those members get to skip certain security measures (leave on that belt!) is that they're supposed to have proved that they aren't a threat.

And how does one go about proving that? Mostly, you spend $85 to apply and undergo a brief background check. "There's no technology per se that makes it inherently safe," says Kevin Curran, an IEEE Senior Member and senior lecturer in computer science at Ulster University, "unless you count the fingerprint scans [that accompany the application]. But the TSA do believe in this intelligence-driven, risk-based approach to security."

TSA Precheck security

Risk reduction

PreCheck's numbers were crunched by Mark G. Stewart for the Journal of Transportation Security, and came up favorably. Stewart concluded that not only does the PreCheck system reduce the already low risk of a bomb slipping past screeners and getting onto a plane; it also has co-benefits: by "improving the passenger experience," it can have several billion dollars a year in knock-on economic effects.

TSA Precheck security

Cash cow?

Of course, the program costs money to administer, and it's not clear if those costs are covered by the $85 per person fee to apply. "It's quite possible that the extra fees do cover the extra costs," says Ulster University's Curran. But that may be largely beside the point, as Stewart's article hints. "Costing the system is difficult, as it affects the US national economy in many ways," Curran continues. "Slower security lanes means less business travelers. How do you cost that? Also, slower lanes and stringent security can lead to fewer travelers to the USA. How do you cost those who choose not to travel here?"

TSA Precheck security

Trouble beneath the surface

And yet PreCheck has plenty of critics too. Perhaps the most prominent is Kip Hawley, who himself was TSA Administrator for much of the '00s, before PreCheck was implemented. In a scathing op-ed, Hawley takes on that "intelligence-driven, risk-based security strategy" language, which the TSA promotes. "The absence of negative information about a person doesn’t mean he or she is trustworthy," he thunders. "There is no screening algorithm and no database check that can accurately predict human behavior." In other words, there really is no technological magic bullet happening behind the scenes: the TSA is just trying to extrapolate future behavior from the past.

TSA Precheck security

Lost in transmission

And the technology does underlay the system has had its share of hiccups. The system hinges on what's called a known traveler number—a number assigned to passengers who have been screened by the program, and is also used in similar programs like Global Entry, which applies to international flights. Unfortunately, in a series of flubs that could have been predicted by anyone who works with databases, people found that their known traveler number wasn't being properly associated with their tickets, the result of communications glitches between airlines, booking systems, and the TSA.

TSA Precheck security
REUTERS/Daniel Munoz

Queue mismatch

But in the end, it seems that more of PreCheck's problems are organizational than technological—which should come as a warning to any security pro convinced that technical barriers are all that stand in the way of perfection. PreCheck's biggest difficulty? It's pretty simple: not enough people are signing up for it. The plan was for enrollment to have hit 25 million people by this year; the actual numbers are less than half that. And the most obvious consequence to that? The lines set aside for PreCheck are empty, and the ones for the plebs are jammed full. And that's why you've been getting invited into PreCheck lines over the past couple of years—even though, from a security standpoint, you haven't earned the right to keep your shoes on.

TSA Precheck security

Back of the line

It's the result of what Hawley calls the "impossible mandate" imposed on the TSA, to both secure airports, keep people moving through quickly, and implement the PreCheck system. Now the pendulum is swinging back towards strict screening again, and so those glory days are over, because inviting just anyone into those lines undermines the whole point of having them in the first place—assuming, of course, that you believe a background check really makes you safer. Ulster University's Curran muses that much of the process's utility lies in the realm of "security theater," with the extra background check mostly making passengers feel safer.

TSA Precheck security
REUTERS/Andrew Kelly

Beyond the air

Despite all these hitches, TSA PreCheck isn't going anywhere soon—in fact, the agency is hoping that its enrollment numbers will finally start to climb this year. We'll find out! But perhaps more importantly, the concept is spreading: it's starting to be implemented at sports stadiums, for instance. Here too, it's billed as "high tech" in the headlines when the actual technology involved isn't much more than a fingerprint reader and a database. But with arenas interested in ancillary revenue sources, it remains to be seen whether they'll avoid the TSA's problems—or if you might find yourself casually ushered into the fast lane at a baseball game too.

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