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Iris recognition at airports uses eye-catching technology

The scanning process takes advantage of the natural patterns in people's irises, digitizing them for identification purposes  

July 24, 2000
Web posted at: 6:25 p.m. EDT (2225 GMT)

  • Quick facts on iris recognition

    (CNN) -- Iris-recognition technology was designed to be less intrusive than retina scans, which often require infrared rays or bright light to get an accurate reading. Scientists also say a person's retina can change with age, while an iris remains intact. And no two iris blueprints are mathematically alike, even between identical twins and triplets.

    Charlotte/Douglas International Airport in North Carolina is acting as a testing ground for the biometric technology beginning this week. EyeTicket Corp., headquartered in McLean, Virginia, is the exclusive provider of the technique for both airline passengers and personnel.

    To record an individual's iris code, a black-and-white video camera uses 30 frames per second to zoom in on the eye and "grab" a sharp image of the iris. A low-level incandescent light illuminates the iris so the video camera can focus on it, but the light is barely noticeable and used strictly to assist the camera. One of the frames is then digitized and stored in a PC database of enrolled users. The whole procedure takes less than a few seconds, and can be fully computerized with voice prompts and auto focus.

    Eye-scanning system could reduce airport lines, hassles

    At an airport, for example, a person's name and airline information accompanies the iris code, but to protect people's privacy no further data -- a Social Security number, for example -- is collected. The stored file is only 512 bytes with a resolution of 640 x 480, allowing for massive storage on a computer's hard drive. Manufacturers of the technology say they have made assurances that the databases will not be shared with other organizations.

    Glasses and contact lenses, even colored ones, do not interfere with the process. In addition, recent medical advances such as refractive surgery, cataract surgery and cornea transplants do not change the iris' characteristics. In fact, it is impossible to modify the iris without risking blindness. And even a blind person can participate. As long as a sightless eye has an iris, that eye can be identified by iris recognition.

    The camera can be set at a distance of four inches (10 centimeters) to 40 inches (one meter), depending on the scanning environment. When iris recognition is used for logging on to a personal computer or checking in at an airport, people need to be somewhat closer to the camera. An automatic cash machine, on the other hand, does not require such nearness.

    A camera, set from 4 inches to a meter away from the user, takes a digital picture of the iris  

    The term "scanning" can be misleading, said David Johnston, vice president of marketing at IrisScan Inc., the Marlton, New Jersey, company that holds worldwide patents on iris recognition. He says no scanning is actually performed since the eye is simply photographed. IrisScan licenses its iris-recognition software and offers it to firms like EyeTicket.

    An iris has a mesh-like texture to it, with numerous overlays and patterns that can measured by the computer, said Johnston. The iris-recognition software uses about 260 "degrees of freedom," or points of reference, to search the data for a match. By comparison, the best fingerprint technology uses about 60 to 70 degrees of freedom, he noted.

    Cost has been the biggest deterrent to implementing the technology, said Johnston, but it is now becoming more affordable for companies ranging from security firms to airports to incorporate.

    Evan Smith, EyeTicket's senior vice president, said his company has also developed a system of doors in response to a recent security concern raised by the Federal Aviation Administration.

    The matter arose when the iris-recognition software was implemented for security purposes around the airport terminal, designed to allow only authorized people to enter certain areas. But the FAA found that an unauthorized person had time to dash in behind an authorized person once the iris-recognition allowed access -- a practice it termed "piggybacking" or "tail-gating."

    EyeTicket will install revolving doorways, the first of which was unveiled Monday at the Charlotte/Douglas airport, to stop that practice, officials said. The first door opens upon iris recognition and then closes behind the person, leaving them in a small portal. The next door will only open upon confirming there is just one person in the portal.

    Proponents of the iris scanning technology say it could soon be widely accepted in many different locations as more people are introduced to its convenience.

    Fact Box:
  • Probability of two irises producing exactly the same code: 1 in 10 to the 78th power
  • Independent variables (degrees of freedom) extracted: 266
  • IrisCode record size: 512 bytes
  • Operating systems compatibility: DOS and Windows (NT/95)
  • Average identification speed (database of 100,000 IrisCode records): one to two seconds
  • Source - IrisScan Inc.

    Iris scans take off at airports
    July 19, 2000

    EyeTicket Corporation
    Charlotte/Douglas International Airport
    U.S. Airways

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