Traveler using iris scan security system
Amsterdam (6/17/02)- Security systems that scan the iris of your eye
may soon help speed you through those long lines at the airport.
Following the events of September 11th, there has been increased emphasis
on improving security while minimizing inconvenience to travelers. Iris recognition
systems would seem to fit the bill. Such systems are now in limited use at
several airports in Europe and the United States.
These systems take advantage of random variations in the visible features
the iris, the colored ring around the pupil. After a traveler has his iris
scanned once, a unique file is placed in a database. Subsequently, the traveler
simply looks at a suitably equipped camera that scans and checks the iris
in little more than one second.
Amsterdam Airport Schiphol began using its automated border passage system
in October 2001. That system combines iris recognition technology and an advanced
smart card. It is the first of its kind to use iris recognition to secure
border control. New enhancements to the system will extend its functions to
include ticketing, check in, screening and boarding. Schiphol will also use
an iris recognition system behind the scenes to provide secure access to restricted
An iris recognition system is also being evaluated at London's Heathrow airport.
Frequent transatlantic travelers on British Airways and Virgin now use the
EyeTicket Jetstream system to speed them through passport control at the world's
busiest airport. The system is similar to that in use at Schiphol. A similar
system is in place in Germany's Frankfurt Airport. While the North American
experience has so far been limited to the Charlotte/Douglas International
Airport, plans are now underway to install similar systems at JFK in New York,
Dulles in Washington, DC and at 14 international airports in Canada.
The iris is the only internal organ normally visible
from outside the body.
The correct plural for iris is irides
Iris scanning takes advantage of random variations in the visible features
the iris, the colored part of the eye. The iris consists largely of a system
of muscle that expand and contract the pupil in response to changing lighting
conditions. The details of each iris are phenotypically unique, that is, no
two are exactly alike, not even among twins, not even in your own two eyes.
The structure of the iris develops in the embryo, assuming its lifelong character
by the seventh or eighth month. Some color changes can occur in the first
months of life, which explains why some babies who are born with blue eyes
may end up with brown or some other color.
After taking a picture of the eye, the system samples the radial and angular
variations of each individual iris to form an IrisCode, a digital file that
serves as a reference in database. At 512 bytes, the file is quite small,
since it is a hexadecimal code reference rather than an actual iris image.
Research confirms an extraordinarily high level of statistical reliability
for the system.
A person using the system simply looks into a camera. The computer program
then locates the iris. Next, the system locates the iris' outer and inner
edges. The monochrome camera uses both visible and infrared (700-900nm) light.
The program maps segments of the iris into hundreds of vectors. Position,
orientation and spatial frequency provide the basis for calculation of the
IrisCode. The system also manages to take into account normal changes in the
eye. For example, the system compensates for papillary expansion and contraction.
It can also detect reflections from the cornea.
Is there any way to fool the system? Researchers attempted to do this by
creating contact lenses with irides printed on them. The system had no trouble
spotting the fakes. Some of the newer drug treatments for glaucoma include
changes in iris pigmentation among their side effects. This should not be
a problem since iris recognition systems rely on monochrome images, the developers
Iris recognition technology is finding its way into many aspects
of everyday life. England's Nationwide Building Society (a bank), for example,
replaced PIN numbers with iris recognition at its ATM machines in 1998. The
systems now form part of many building access systems in government and industry.
More recently, products have become available to screen computer network users
and to provide secure online transactions. Any application for which you currently
use a password could soon require a quick look at your eye instead.
Identifying the Mystery Woman
recognition systems are also finding unexpected applications. The best know
example involved using iris recognition to confirm the identification of a
mysterious young Afghan woman originally photographed by Nation Geographic
photographer Steve McCurry in 1984. Some 18 years later, McCurry photographed
Sharbat Gula in Afghanistan. At the behest of National Geographic, Dr. John
Daugman, developer of the iris recognition system, then compared the irides
in the photographs using his algorithms. He concluded that the eyes were a