Malintent detection: airport security
Finding the bomb or finding the bomber?
The two models of airport security
In most airports around the world, security is focused on finding bombs. The basic perimeter is controlled with gates and ID checks that let only trusted personnel into secure areas for handling luggage, for performing maintenance on aircraft, etc. Passengers are not considered trusted personnel so as they progress through an airport from check-in to boarding, they are now subjected to numerous checks.
- Airlines submit passenger data to the destination authorities;
- Passengers must submit ID on check-in;
- Checked luggage is scanned before and after check-in;
- Passengers often submit to a full body scan of dubious reliability;
- If the scanners beeps a “false positive“, which they often do, they are patted down.
- They are forbidden from carrying liquids on board;
- Their carry-on bags must be screened;
- People doing the screen often wear glazed expressions on their faces, unless they are chatting with their colleagues. So how sure are we they’ll find that hidden explosive device?
Certainly cursory checks are necessary, no one disputes that. But the unreliability of the current security model coupled with the high cost to our dignity (never mind to taxpayer wallets) should make us look for a new approach.
Israel’s Ben Gurion Airport (TLV) in Tel Aviv has done just that. Their approach to security emphasizes finding the bomber. Rather than spending more and more resources on looking harder for the bomb, and getting marginal returns, security personnel at TLV take a balanced approach and have instead looking for people behaving a certain way.
Passengers arriving at the airport are greeted by polite young ladies, often high school or university students working part time as they go to school. They are asked where they are going, if they are living in Israel or if they were visiting. If visited, they are asked if they enjoyed their visit. As these young ladies, called “selectors” make small talk, they are really looking at how passengers are reacting.
For passengers, enthusiastically praising Israel as a tourist destination is fine, but so is complaining about how bad the food was. Passengers can even be rude to the selectors and say that they’ve never had such an awful experience. The selectors don’t care what passengers answer if they are polite back (of course because they are polite, most passengers are also polite, it’s human nature). They just direct passengers to line number one, wish then a nice day, and move on to the next person.
But if they notice a passenger is behaving strangely, or that they are fidgeting too much, then they spring into action! Because of conscription, they have received Israeli military training after all. They direct the passenger to line number TWO (aha!) then wish them a nice day, and move on to the next person.
Neat, don’t you think?
There is no profiling, no agonizing soul searching, no accusatory judgement. The selector make a simple assessment: does this person need to be checked further?
Line two involves more intense questioning as the passenger’s luggage is thoroughly searched. Every one is still very polite at this point. Unless they actually find something bad in the luggage, the passenger has a 99% chance of passing this test no matter how bad a mood they are in. And if they do fail that test, then they are interviewed at length in a private room.
Ben Gurion Airport-Passenger flow through security
It’s worth noting that the last terrorist incident at Ben Gurion was in the early 1970s and was carried out by terrorists who were arriving passengers. No flight originating at Ben Gurion was ever hijacked or blown up.
Contrast that with the underwear bomber. He would never have made it through any of the layers. He would have wound up interrogated in a private room and any professional security officer would have known his intentions. He would have been searched and the bomb found, but it would have been found because the bomber would have been found.
This is what malintent detection is all about. Sorting through six million passengers a year, or an average of 16,000 passengers a day, then each day searching through the luggage of about 300 people, and then privately interviewing fewer than five passengers a day.
This works very well in Israel because the population is very security conscious and because the number of the manageable number of passengers that selectors must assess. This would not work at Heathrow airport which handles 70 million passengers a year, often with little time because they are just transiting.
Can the process be automated? Yes, and you’ll find malintent detection technology described in my last post.
The next post will deal on other applications for this technology and on the limitations of the technology. The last post in this series will deal with the trade-off between security and privacy and on the need for applying strict governance to the use the authorities make of malintent detection.
Copyright 2011, Vincent Poirier
Disclaimer: I am helping promote a malintent technology system developer in Japan, so please be aware of the possible conflict of interest.
