Shabtai Shoval got his idea while watching Vanilla Sky, a movie set in a futuristic world, where it is possible to identify criminals before they commit crimes, on the basis of their intentions. Shoval left the cinema with one question on his mind, Was it possible to create such a system in today's reality and using today's tools? After consulting friends in the Israeli Security Agency (ISA, formerly known as the General Security Services or GSS), Israel Police, and the high-tech industry, and with polygraph, investigations, terrorism, and software experts, he concluded that it was possible.
This was the foundation of SDS, which has already begun cooperating with the US Transportation Security Authority (TSA) to build a system for spotting suspects at US airports, even when there is no solid evidence that they're about to commit a crime - no explosives, knife, or even forged documents.
"The terrorists who attacked the World Trade Center entered and left the US dozens of times under their real identities," notes Shoval. "No one suspected them. The $4 billion that the US is investing on systems to spot weapons at airports could not have prevented their entry."
How is it possible to spot a person's intentions, to read his or her thoughts, in effect? The only method available that makes this possible to a certain extent is the polygraph, and many experts disagree about its reliability and application. The results of polygraph tests are inadmissible as evidence in court, for example, since they are not considered reliable beyond a reasonable doubt. Shoval, however, says police and ISA investigators believe that the polygraph is valid, and its use is very widespread, since the reasonable doubt test is not always essential in investigations.
"SDS utilizes the principles of the polygraph, but our system is not, and isn’t meant to be, a polygraph, for several reasons," says Shoval. "The first reason is that the polygraph is designed to spot a lie. But a terrorist is trained to persuade himself that he is not lying, and his concept of a lie isn’t always the same as that of the person conducting the test. It's a cultural thing. Our system therefore doesn’t try to catch a lie, but the fear of being caught."
Does a terrorist about to commit suicide show emotional patterns indicating fear, even fear of being caught? Shoval claims that the defense forces' experience of terrorists shows that the fear is there.
Testing the limits of the reasonable
An ordinary polygraph test takes place as follows: the investigator asks the person being tested to answer several questions two which both parties know the correct answer, and then asks questions to which the answers are clearly lies. The investigator then asks the person several questions, including those related to the truth-or-lie questions the investigator is interested in. Through examination of electric pulses in the skin and blood pressure, it is possible to know whether a question triggers in the person being questioned a reaction resembling his or her reaction to a lie.
Against what does SDS calibrate the fear of being caught? One of the company's critical assets is a collection of words in dozens of languages that trigger a different response in a suspect linked somehow to the world of terrorism, compared with the response of a person with no link.
Shoval gives the example of the Hebrew word "tadrikh" (briefing). "A person about to carry out a terrorist attack usually undergoes a briefing. A person who hasn’t had a briefing that has to be concealed will react apathetically to this word. Another example is Semtex, an explosive that only a few people are exposed to.
"Our advantage, assuming that the system is installed in a major US airport, is that we're exposed to thousands of people from every culture, who speak every language. We can build a profile of a response by a 'reasonable Pakistani', or a 'reasonable Iranian' to a string of our words. The system constantly examines and learns this reasonable response.
"We look for two gaps. One is the difference between the interviewee's responses to our special words and the reasonable response to these words. The other is the difference between the interviewee's response to suspicious words and the response to ordinary words. We're not catching drug traffickers, smugglers or pedophiles, only people planning to carry out terrorist attacks."
SDS's system is built differently from a polygraph. Instead of attaching electrodes, a lengthy procedure that puts an interviewee under pressure, skin conductivity is tested through the palm of the hand. The interviewee places his or her hand on the machine, and with the other hand selects the language for the questions. The interviewee is shown a range of words, including the suspect words, and his or her response to them is measured. The test takes three minutes. "The US Department of Homeland Security's policy is to test only 20% of aliens, depending on their country of origin. On the basis of this condition, 20 terminals are enough for a large airport," says Shoval.
Tests at US airports
The Department of Homeland Security is the body that buys airport surveillance systems. SDS recently marked a major achievement, winning a Department of Homeland Security tender for testing a system for identifying suspects at an airport. The tender means money from the Department of Homeland Security, and opportunities to conduct trials at US airports.
Under Department of Homeland Security procedures, the system may point to 4% of people passing through an airport as suspects. Suspects are handed over to human interrogators. The 4% range is, of course, a lot larger than the number of terrorists passing through airports, and is the figure that enables SDS to take its system out of the realm of science fiction into reality. The system does not spot terrorists. It spots suspects.
"Globes": You look for suspicious responses, but people are different from one another. Maybe a suspect is mentally disturbed, or merely weird? Maybe his response will be different from that of other people of his nationality, because his parents were immigrants?
Shoval: "In such a case, we'll see a very different response from that of other people of his nationality, but we won't see an exceptional response to the special words. His responses to all the words will be equally odd."
Can a terrorist develop a response to beat the system?
"Terrorists don’t know our special words, which we constantly change, nor do they know the 'reasonable response', against which they're compared. It will therefore be very difficult for them to train. A terrorist can try to teach himself to mute his responses, or even take a tranquilizer. But in that case, his response will be different from that of other people of his nationality."
What if a terrorist doesn’t chose his native tongue, in order to avoid the special words?
"He will respond differently from the way the average English-speaker responds, both because it isn’t his native tongue, and because he won't understand some of the words. It's impossible to outsmart this machine; anyone who tries to be clever is screwed."
What about someone who's very interested in terrorism, but isn’t a terrorist? Maybe he's a member of Pakistani security?
"It's possible, although not at all certain, that such a person would be a suspect within the 4% permissible range. If he is, he'll have to explain himself to the human interrogator."
How is the system tested? After all, you can't collect terrorists to consent to being tested.
"So far, we've only tested and calibrated the system on Israelis. As I said, the goal is to create a system that tests the fear of being caught, so some of the subjects were given a mission, and others weren’t. The system was able to identify the subjects who were given a mission. We later specifically tested stressful missions, such as taking something from the boss's office. The system identified the people carrying out the stressful mission."
The Department of Homeland Security allows you to suspect 4% of legitimate people. What is your margin of error in the other direction. Is the system certain of catching every terrorist, or will one periodically get through?
"We believe that maybe one out of dozens of terrorists can slip through the system. It's not perfect, but that's how it is with security - you can only do your best. You want things to make as difficult as possible for terrorists. If 50 terrorists are caught and one gets away, we'll be pleased, and so will the authorities."
Don’t tell the terrorists how it works
Shoval previously worked for the Ministry of Defense, and was director of Comverse Technology's (Nasdaq: CMVT) TVGate division. Ziggi Horowitz, former chief of the police's polygraph unit and now the head of a polygraph institute, worked in the same building. They developed SDS's system together. Another partner in the company is Maj.-Gen. (res.) Amiram Levin, formerly deputy head of the Institute for Intelligence and Special Operations (Mossad) and IDF OC Central Command, and now a businessman.
The field is very hot, and there must be other companies mulling similar ventures.
"As far as I know, there are no systems that even come close to working on the same principle. There are systems that try to spot a lie through voice frequencies, but it hasn’t yet been proved that voice is an effective physiological index of intent. Another system is trying to spot excitement through body temperature, but what if the terrorist has taken a tranquilizer? None of these systems is as specific as ours. Even if someone were to read this article and decide to imitate us, he would face at least a two to three-year development hurdle."
Have you patented the method?
"We haven’t. What's a patent after all? It means that you must disclose your know-how in full, and then someone can copy you, and, at best, you can sue him. In addition, although terrorists will have trouble confounding the system, it's foolish to give them as much information as possible, as required in a patent. In fact, the law permits a suit even without a patent, if there is proof of theft of intellectual property. We gain nothing from a patent."
What's your next step?
"Luckily, we're in an all-or-nothing field. The Americans know that if they order the system only for JFK Airport, all the terrorists will switch to another one. The closure must be either hermetic, or nonexistent. Therefore, if the Department of Homeland Security chooses to work with SDS, we'll hold an IPO the next day.
"Later, we can adapt the system to examine suspects in other areas: criminals; drugs; and employee loyalty in security positions. But the software will have to be adapted for these purposes."
Published by Globes [online], Israel business news - www.globes.co.il - on April 20, 2005