IRIS/RETINA BIOMETRICS

Retina The retina is a thin layer of cells at the back of the eyeball of vertebrates. eyeballvertebrates eyeballvertebrates It is the part of the eye which converts light into nervous signals. light The retina contains photoreceptor cells (rods and cones) which receive the light; the resulting neural signals then undergo complex processing by other neurons of the retina, and are transformed into action potentials in retinal ganglion cells whose axons form the optic nerve. photoreceptorrods cones neurons action potentials axonsoptic nervephotoreceptorrods cones neurons action potentials axonsoptic nerve The retina not only detects light, it also plays a significant part in visual perception. visual perceptionvisual perception In embryonal development, the retina and the optic nerve originate as outgrowths of the brain. embryonal developmentbrainembryonal developmentbrain The unique structure of the blood vessels in the retina has been used for biometric identification. blood vesselsbiometricblood vesselsbiometric

To brain The retina, in the back of your eye, has cells that are sensitive to light. They connect directly to your brain. Rods sense brightness Cones sense color

Biometrics which analyze the complex and unique characteristics of the eye can be divided into two different fields: –iris biometrics - iris is the colored band of tissue that surrounds the pupil of the eye. –retina biometrics - retina is the layer of blood vessels at the back of the eye. An iris recognition system uses a video camera to capture the sample while the software compares the resulting data against stored templates.

Understanding Iris Recognition Iris scan biometrics employs the unique characteristics and features of the human iris in order to verify the identity of an individual. The iris is the area of the eye where the pigmented or colored circle, usually brown or blue, rings the dark pupil of the eye.

Iris recognition systems use small, high-quality cameras to capture a black and white high- resolution photograph of the iris. This process takes only one to two seconds and provides the details of the iris that are mapped, recorded and stored for future matching/verification Once the image is captured, the iris’ elastic connective tissue—called the trabecular meshwork—is analyzed, processed into an optical “fingerprint,” and translated into a digital form. Given the stable physical traits of the iris, this technology is considered to be one of the safest, fastest, and most accurate, noninvasive biometric technologies. The iris is differentiated by several characteristics including ligaments, furrows, ridges, crypts, rings, corona, freckles, and a sigzag collarette.

An Iris Reader

Iris

An Iris Recognition Process

The inner edge of the iris is located by an iris-scan algorithm which maps the iris’ distinct patterns and characteristics. Iris’ are composed before birth and, except in the event of an injury to the eyeball, remain unchanged throughout an individual’s lifetime. Iris patterns are extremely complex, carry an astonishing amount of information and have over 200 unique spots. The fact that an individual’s right and left eyes are different and that patterns are easy to capture, establishes iris-scan technology as one of the biometrics that is very resistant to false matching and fraud.

The false acceptance rate for iris recognition systems is 1 in 1.2 million, statistically better than the average fingerprint recognition system. The real benefit is in the false- rejection rate, a measure of authenticated users who are rejected. Fingerprint scanners have a 3 percent false-rejection rate, whereas iris scanning systems boast rates at the 0 percent level

Eyeglasses and contact lenses present no problems to the quality of the image and the iris-scan systems test for a live eye by checking for the normal continuous fluctuation in pupil size.

Spoofing the Iris The iris is extremely difficult trait to spoof, yet there have been attempts to do just that Attacks on the iris fall into the following categories: –Attacking the physical iris –Using artfacts –Attacking the communication –Compromising the teplate –Attacking the fallback system

Advantages of the Iris for Identification Highly protected, internal organ of the eye Externally visible; patterns imaged from a distance Iris patterns possess a high degree of randomness Changing pupil size confirms natural physiology Limited genetic penetrance of iris patterns Patterns apparently stable throughout life Encoding and decision-making are tractable

Disadvantages of the Iris for Identification Small target (1 cm) to acquire from a distance (1 m) Moving target...within another Located behind a curved, wet, reflecting surface Obscured by eyelashes, lenses, reflections Partially occluded by eyelids, often drooping Deforms non-elastically as pupil changes size Illumination should not be visible or bright Some negative (Orwellian) connotations

Retinal Recognition System Retina scans are performed by directing a low-intensity infrared light to capture the unique retina characteristics. An area known as the face, situated at the center of the retina, is scanned and the unique pattern of the blood vessels is captured. Retina recognition technology captures and analyzes the patterns of blood vessels on the thin nerve on the back of the eyeball that processes light entering through the pupil. Retinal patterns are highly distinctive traits. Every eye has its own totally unique pattern of blood vessels; even the eyes of identical twins are distinct. Although each pattern normally remains stable over a person’s lifetime, it can be affected by disease such as glaucoma, diabetes, high blood pressure, and autoimmune deficiency syndrome. Retina biometrics is considered to be the best biometric performers. However, despite is accuracy, this technique is often thought to be inconvenient and intrusive. And so, it is difficult to gain general acceptance by the end user. Eye and retinal scanner are ineffectual with the blind and those who have cataracts.

The fact that the retina is small, internal, and difficult to measure makes capturing its image more difficult than most biometric technologies. An individual must position the eye very close to the lens of the retina-scan device, gaze directly into the lens, and remain perfectly still while focusing on a revolving light while a small camera scans the retina through the pupil. Any movement can interfere with the process and can require restarting. Enrollment can easily take more than a minute. The generated template is only 96 bytes, one of the smallest of the biometric technologies. It is one of the most accurate and most reliable of the biometric technologies, and it is used for access control in government and military environments that require very high security, such as nuclear weapons and research sites. However, the great degree of effort and cooperation required of users has made it one of the least deployed of all the biometric technologies. Newer, faster, better retina recognition technologies are being developed.