Stability of iris questioned

04/08/10

Iris patterns are generally thought of as being unique and stable throughout a person's life - indeed these characteristics are crucial in order to make any good biometric trait. New research, however, has been reported that questions just how stable an iris is over time, something that could affect the normally impressive performance of iris recognition systems on large populations.

An article in New Scientist reports that iris scans from a particular eye can alter over time, potentially meaning that a system will fail to match an iris if the template it matches against is very old.
The structures creating distinctive iris patterns are complete by the eighth month of gestation (although pigmentation continues into the first years after birth). However,  Kevin Bowyer at the University of Notre Dame in Indiana and his colleagues say they now have evidence that the Hamming distance increases over time for scans of the same eye.  Hamming distance is an important statistical measure - essentially if the Hamming distance is found to be below the decision threshold, then a positive identification is made. So if Hamming distance increases over time then there is an increased chance of false rejection by the system.
Bowyer and Co. initially compared pairs of scans of 26 irises taken two months apart with scans made four years apart. According to the report in New Scientist (based on recently submitted analysis) the team measured an increase of 0.018 per cent over the period.
So does this make a difference? Especially given the scale of some projects now under consideration, such as the UIDAI scheme in India. Probably not, it seems…
"Even if this finding is true, it is no cause for concern," says John Daugman of the University of Cambridge. He says a real-world system may have a false rejection rate of the order of 1 in 250 million, so the increase in Hamming distance measured by Bowyer would result in a false rejection rate of just 0.7 in 100 million scans after four years.
Subscribe to our free newsletter
Follow us on Twitter
Join us on LinkedIn

Article Comments

No reviews have been submitted

Please add a comment on this article from the Add Comment below.

Please Login or Register.

Login or Register

This article appears in :-
Could ageing eyes alter iris recognition?
Could ageing eyes alter iris recognition?

Other Site News

Morpho signs large biometric agreement with State Bank of India 19 February 2013
Suprema fingerprint scanner certified for India's UID Project 07 February 2013
DigitalPersona receive STQC Certification for UIDAI 05 February 2013
High security needs drive biometrics adoption in India 20 December 2012
Indian biometric collection to continue 12 December 2012
More articles >>

Press Releases

Cross Match receives Certification from STQC for India’s UID Program 12 October 2011
Bank signs MoU for state implementation of UIDAI project 20 July 2011
Bank of India begins UID enrolment project 17 June 2011
Morpho’s 10 fingerprint image capture terminal receives UIDAI certification 23 November 2010
Biometric Certification Agency Selected by UIDAI 02 July 2010
More articles >>
Share |

Sponsored Links

ievo Ievo™ readers are quickly representing the future of fingerprint access control by challenging your perception of biometrics. Unlike traditional security products Ievo readers perform even with substances present on the skin. Visit Ievo’s directory page to find out more!
id3 Technologies id3 Technologies is an innovative and creative company focused on providing fingerprint recognition. All id3 Technologies fingerprint algorithms are sensor independent, interoperable and certified by NIST MINEX. Id3 provides fast, accurate and convenient products.
3M Cogent 3M Cogent is a global biometric identification solutions provider to governments, law enforcement agencies, and commercial enterprises. 3M Cogent delivers the fastest, most accurate, and most sophisticated yet reliable biometric identification solutions in the world.
Speed Identity Speed Identity is an innovative Swedish technology company supplying integrated biometric data capture solutions. The new Speed Capture G3 is the first cross-functional form factor.