“One iris biometric marketing claim has been that the iris allowed ‘a single enrolment for a lifetime’. This claim is now proven to be false,” he says.The iris isn't the only thing that is changing over time, though. The matching algorithm changes, too. It seems to me that it's important to know whether iris matching algorithms are becoming "smarter" faster than a person's iris can change.
The likelihood of software incorrectly matching two irises from different people is around 1 in 2 million (known as the false match rate). So in practical terms, Bowyer’s results suggest that the false match rate for a system would increase to 2.5 in 2 million after three years had elapsed. This rate sounds low, but the effect appears to be cumulative, says Bowyer: “So although you might not really notice the problem after one year or two years, after five or ten years it can become a huge problem,” he explains.
But some are not convinced that the iris ageing effect will make a noticeable difference to the false match rate — even in huge national iris-identification schemes such as India's, which so far has more than 200 million people enrolled. Biometrics expert Vijayakumar Bhagavatula of Carnegie Mellon University in Pittsburgh, Pennsylvania, says: “In my opinion, the impact of this research is to suggest that iris templates should be periodically updated.”
Customers should probably keep current on their support contract, just in case.
