Which Travelers Have 'Hostile Intent'?
Biometric Device May Have the Answer
By JONATHAN KARP and LAURA MECKLER
At airport security checkpoints in Knoxville, Tenn. this summer, scores of
departing passengers were chosen to step behind a curtain, sit in a metallic
oval booth and don headphones.
With one hand inserted into a sensor that monitors physical responses, the
travelers used the other hand to answer questions on a touch screen about
their plans. A machine measured biometric responses -- blood pressure, pulse
and sweat levels -- that then were analyzed by software. The idea was to
ferret out U.S. officials who were carrying out carefully constructed but
make-believe terrorist missions.
The trial of the Israeli-developed system represents an effort by the U.S.
Transportation Security Administration to determine whether technology can
spot passengers who have "hostile intent." In effect, the screening system
attempts to mechanize Israel's vaunted airport-security process by using
algorithms, artificial-intelligence software and polygraph principles.
[The Israeli-developed system combines questions and biometric measurements
to determine if a passenger should undergo screening by security officials.]
The Israeli-developed system combines questions and biometric measurements
to determine if a passenger should undergo screening by security officials.
Neither the TSA nor Suspect Detection Systems Ltd., the Israeli company,
will discuss the Knoxville trial, whose primary goal was to uncover the
designated bad guys, not to identify threats among real travelers. They
won't even say what questions were asked of travelers, though the system is
generally designed to measure physical responses to hot-button questions
like "Are you planning to immigrate illegally?" or "Are you smuggling
The test alone signals a push for new ways to combat terrorists using
technology. Authorities are convinced that beyond hunting for weapons and
dangerous liquids brought on board airliners, the battle for security lies
in identifying dangerous passengers.
The method isn't intended to catch specific lies, says Shabtai Shoval, chief
executive of Suspect Detection Systems, the start-up business behind the
technology dubbed Cogito. "What we are looking for are patterns of behavior
that indicate something all terrorists have: the fear of being caught," he
Security specialists say such technology can enhance, but not replace,
existing detection machines and procedures. Some independent experts who are
familiar with Mr. Shoval's product say that while his technology isn't yet
mature, it has potential. "You can't replicate the Israeli system exactly,
but if you can incorporate its philosophy, this technology can be one
element of a better solution," says Doron Bergerbest-Eilon, chief executive
of Asero Worldwide consulting firm and a former senior official in Israel's
To date, the TSA has more confidence in people than machines to detect
suspicious behavior. A small program now is using screening officers to
watch travelers for suspicious behavior. "It may be the only thing I know of
that favors the human solution instead of technology," says TSA chief Kip
The people-based program -- called Screening Passengers by Observation
Technique, or SPOT -- began undergoing tests at Boston's Logan Airport after
9/11 and has expanded to about a dozen airports. Trained teams watch
travelers in security lines and elsewhere. They look for obvious things like
someone wearing a heavy coat on a hot day, but also for subtle signs like
vocal timbre, gestures and tiny facial movements that indicate someone is
trying to disguise an emotion.
TSA officers observe passengers while consulting a list of more than 30
questionable behaviors, each of which has a numerical score. If someone
scores high enough, an officer approaches the person and asks a few
"All you know is there's an emotion being concealed. You have to find out
why the emotion is occurring," says Paul Ekman, a San Francisco psychologist
who pioneered work on facial expressions and is informally advising the TSA.
"You can find out very quickly."
More than 80% of those approached are quickly dismissed, he says. The
explanations for hiding emotions often are innocent: A traveler might be
stressed out from work, worried about missing a flight or sad because a
relative just died. If suspicions remain, the traveler is interviewed at
greater length by a screener with more specialized training. SPOT teams have
identified about 100 people who were trying to smuggle drugs, use fake IDs
and commit other crimes, but not terrorist acts.
The TSA says that, because the program is based on human behavior, not
attributes, it isn't vulnerable to racial profiling. Critics worry it still
could run afoul of civil rights. "Our concern is that giving TSA screeners
this kind of responsibility and discretion can result in their making
decisions not based on solid criteria but on impermissible characteristics
such as race," says Gregory T. Nojeim, associate director of the American
Civil Liberties Union's Washington legislative office.
Mr. Shoval, the Israeli entrepreneur, believes technology-based screening is
the key to rolling out behavior-recognition techniques in the U.S. With
experience in counter-terrorism service and the high-technology industry,
Mr. Shoval developed his Cogito device with leading former Israeli
intelligence officials, polygraph experts and computer-science academics.
Here is the Cogito concept: A passenger enters the booth, swipes his
passport and responds in his choice of language to 15 to 20 questions
generated by factors such as the location, and personal attributes like
nationality, gender and age. The process takes as much as five minutes,
after which the passenger is either cleared or interviewed further by a
At the heart of the system is proprietary software that draws on Israel's
extensive field experience with suicide bombers and security-related
interrogations. The system aims to test the responses to words, in many
languages, that trigger psycho-physiological responses among people with
The technology isn't geared toward detecting general nervousness: Mr. Shoval
says terrorists often are trained to be cool and to conceal stress. Unlike a
standard lie detector, the technology analyzes a person's answers not only
in relation to his other responses but also those of a broader peer group
determined by a range of security considerations. "We can recognize patterns
for people with hostile agendas based on research with Palestinians,
Israelis, Americans and other nationalities in Israel," Mr. Shoval says. "We
haven't tried it with Chinese or Iraqis yet." In theory, the Cogito machine
could be customized for specific cultures, and questions could be tailored
to intelligence about a specific threat.
The biggest challenge in commercializing Cogito is reducing false results
that either implicate innocent travelers or let bad guys slip through. Mr.
Shoval's company has conducted about 10 trials in Israel, including tests in
which control groups were given terrorist missions and tried to beat the
system. In the latest Israeli trial, the system caught 85% of the
role-acting terrorists, meaning that 15% got through, and incorrectly
identified 8% of innocent travelers as potential threats, according to
corporate marketing materials.
The company's goal is to prove it can catch at least 90% of potential
saboteurs -- a 10% false-negative rate -- while inconveniencing just 4% of
Mr. Shoval won a contract for the Knoxville trial in a competitive process.
Next year, Israeli authorities plan to test Cogito at the country's main
international airport and at checkpoints between Israel and the West Bank,
where the goal will be to catch genuine security threats while testing the
logistics of using the system more broadly. The latest prototype costs about
$200,000 a machine.
Even though his expertise is in human observation, U.S. behavior-recognition
expert Dr. Ekman says projects like Cogito deserve a shot. He expects
technology to advance even further, to devices like lasers that measure
people's vital signs from a distance. Within a year, he predicts, such
technology will be able to tell whether someone's "blood pressure or heart
rate is significantly higher than the last 10 people" who entered an
Write to Jonathan Karp at firstname.lastname@example.org and Laura Meckler at