Iris recognition

The iris is the colored circular structure at the front of the eye which controls the diameter and size of the pupil. The texture pattern of each iris is highly unique, providing more information for authentication than a single fingerprint or face.

Daon’s IdentityX platform provides iris authentication for customers when available on their smartphones, alongside more widely available biometric options.

How iris authentication works

The iris pattern is different for both of an individual’s eyes, so capturing information from each together provides the best accuracy. The iris pattern is fixed before birth and remains stable throughout a person’s life.

Although iris color is not used as part of the recognition process, it is a factor: with darker iris colors, the details of the iris pattern cannot be seen using only regular visible light. By illuminating the eyes with near-infrared light, the pattern details can be captured. One or more infrared illuminators and cameras are required to produce this specialized light during capture for iris recognition. Since humans are unable to see infrared light, the capture appears no different than a regular face capture and uses similar hardware to some 3D face solutions.

Iris recognition algorithms work by locating and extracting the iris circular area from the photo of the full eye region, followed by comparing iris areas, from two different captures, using mathematical pattern recognition techniques. Since the iris can vary in size, as the pupil dilates or shrinks, adjustments are made to allow for these changes.

Applications of iris authentication

Specialized iris capture cameras have been in use in government and enterprise applications for many years. For example, some national identity projects use iris to help ensure that each citizen can only obtain a single identity number. In some airports, iris is used both to authenticate travellers and to search against a ‘watch list’ of known suspects. Iris capture devices used have many different form factors ranging from handheld binocular devices, to cameras mounted on walls and within kiosks, to devices that capture iris images at a distance of several meters away while a user is approaching.

Iris has not yet been widely deployed on smartphones, partly due to needing an additional embedded infrared illuminator and a camera sensor that can be used for both infrared iris capture and visible light photos. Sunlight also contains significant amounts of near-infrared light and this can interfere with the iris capture in some outdoor settings, unlike fingerprint or voice. The number of smartphones providing iris recognition is expected to increase in the coming years.

As with other biometrics, precautions should be taken to reduce the probability of spoofing attacks. Since the iris is captured with infrared light, a video or screen image showing a visible light image cannot be easily replayed to spoof the system. Additional iris presentation attack detection (PAD) algorithms examine the texture of the eye to detect printed contact lenses, look for unexpected reflections, and check for changes in pupil size.

Find out more about how Daon’s IdentityX platform allows organizations to authenticate customers using iris recognition, alongside other biometric options.