Detect and serve
Even if your name doesn’t ring alarm bells with Interpol, you will still be subjected to ever more advanced searches to make sure that there’s nothing potentially lifethreatening stashed in your hand luggage.
Archway metal detectors (AMDs) have been standard tech at airports for decades, but their sophistication is now such that they can “detect the foil in a packet of cigarettes”, according to Rafi Sela, head of security at Tel Aviv’s Ben Guiron, dubbed “the world’s safest airport”.
AMDs will also now be able to detect guns or knives made from a range of ferrous, non-ferrous metals and alloys. Nothing is completely fool-proof, though, and there are still ways to trick the technology.
“If you take a piece of wire through in a closed circle it will be detected,” says Sela, “but if you straighten it out, it’s unlikely to be. Also, if that closed loop of wire was parallel to the ground, for example threaded through a
closed shirt collar, it would probably pass through undetected, too.”
It’s because of these flaws that an x-ray team is required, screening around 180 people every single hour at international airports. Working in teams of seven, including a couple of “screeners”, who rotate on 20-minute shifts and analyse what’s seen on screen, flagging up bags that need to be checked.
“The x-ray image interprets the contents of each bag into different colours,” explains former screener turned airport security consultant Richard Ellis. “Orange is for organic material like explosives, liquids and gels; dark blue is for inorganic materials, such as gun metal, sharps, box cutters and IED (improvised explosive device) parts like wires; green represents mixed materials, from plastics to alloys.” A screener also has to identify the outline of an object, which “includes when they’re placed in a manner to confuse,” continues Ellis, “such as a gun standing on its end to mask its profile.”
Images have to be deciphered in less than ten seconds during peak periods and even the x-ray machine itself will test the team of screeners randomly to ensure they’re paying attention. Supervisors can superimpose the image of a banned item – a Threat Image Projection (TIP) – on to any bag in the system to see if it’s picked up.
Security researcher and good-guy hacker Billy Rios warns that even safety measures like these, in the wrong hands, could be potentially dangerous.
“TIPs could, theoretically, be used to project the image of a legal item over a gun, knife or bomb part,” he explains, “using a basic hacker tactic called an SQL injection attack. This involves entering a string of letters in the software to bypass the supervisor’s login and gain control of the airport’s baggage system.” The only way to guard against this, claims Rios, is to stop unauthorised use of the terminal and have a high turnover of new software.
The x-ray isn’t the last line of defence, though. Bag searchers also have the option of cotton swabbing any carry-on items. They do this with a portable machine that is basically a low-level spectrum analyzer, able to identify the chemical signature of bomb-making materials and explosives in seconds. Unfortunately, the machine raises false positives when it detects fertilizers and heart medicines, so if you’re a farmer with a heart condition you may need to leave for the airport a little early.