A living passport
Thanks to John Daugman's 2001 patent, iris recognition left the science fiction realm and became possible in real life. The 52-year-old professor at Cambridge University developed a computer algorithm that turns the eye into an electronic fingerprint.
At a glance
Inventor: John Daugman (GB)
Invention: Iris recognition
Company: University of Cambridge
What if passports became obsolete? What if you didn't have to remember any passwords, door codes or other information that the human brain tends to forget all too easily? And what if you could open doors and pass checkpoints by simply glancing at a computer camera?
All previous attempts to develop such an eye recognition system failed because of the incredibly random patterns that characterise the human iris - computers simply couldn't recognise them.
The puzzle was eventually solved by British inventor John Daugman.
He suggested that the very randomness found in the iris could be the key to it all.
Starting in 1990, Daugman developed an algorithm employing a type of reverse approach. Looking into Daugman's algorithm camera, a person "fails" a test of statistical independence against an image of his or her same eye, while simultaneously being guaranteed of "passing" that test against every other eye.
The system works only if the person has enrolled in a database, from which the iris recognition system then determines who stands in front of the camera. It does so at breathtaking speeds - roughly a second for one million crosschecks.
The technology has become increasingly popular with governments, which use it to supplement tight security at their airports and border control points. Because iris patterns have much more randomness than fingerprints, their probability of false matches is much lower.
At Schiphol Airport in Amsterdam, passengers enrolled in an eye recognition program can enter the country without presenting their passport to a human officer. Instead, they just look at an iris camera, and the gate opens automatically.
In the United Kingdom, a similar eye recognition system enrolled its millionth passenger in 2008. In the United Arab Emirates, travellers are also checked by a networked, iris-based border control system. According to the UAE Interior Ministry, by 2007 the system had performed more than five trillion iris comparisons without a single false match.
These days, Daugman is constantly working to improve the system. He also serves as a consultant for companies that are using his algorithms, and he has resumed teaching at Cambridge.