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The system, although considered to be very advanced at the time, was quite expensive, and bulky to deploy and maintain. But eventually, just a couple of years ago, Iridian Technologies was bought out by a much larger Biometrics vendor, and at the same time, the patents surrounding the original algorithms and technology also expired, thus breaking the monopoly which was held for such a long time.

As a result, there has been a huge explosion of iris recognition just in the past couple of years, offering many new types and kinds of products and solutions for the customer. The advantage to this of course is that the customer now has a much greater depth and breadth of picking and even customizing their own iris recognition solution which will fit their exact needs and requirements, unlike before, where people were basically forced to buy just one product or solution.

In fact, iris recognition has developed so quickly that now images of the iris can be captured at much greater distances, as well as when people are in movement. Previously, an end user had to stand directly in front of the iris recognition camera, at a very close proximity. And now, even the unique pattern of the blood vessels can also be scanned, and this will be examined after the section on retinal recognition.

The Physiological Structure of The Iris

The iris lies between the pupil and the white of the eye, which is known as the sclera. The color of the iris varies from individual to individual, but there is a commonality to the colors, and these include green, blue, brown, and in remote cases, even a hazel color can occur. And in even in the most extreme cases, a combination of these colors can be seen in the iris. The color of the iris is primarily determined by the DNA code inherited from our parents.

The unique patterns of the iris starts to form when the human embryo is conceived, usually at about this happens at about the third month during the third month of fetal gestation. The phenotype of the iris is shaped and formed in a process known as chaotic morphogenesis, and the unique structures of the iris are completely formed during the first two years of child development.

The primary purpose of the iris is to control the diameter and the size of the pupil. The pupil is that part of the eye which allows for light to enter into the eye, which in turn reaches the retina, which is located in the back of the eye. Of course, the amount of light which can enter the pupil is a direct function of how much it can expand and contract, which is governed by the muscles of the iris. The iris is primarily composed of two layers: (1) A fibrovascular tissue known as the stroma, and (2) The stroma is in turn connected to a grouping of muscles known as the sphincter muscles.

It is this muscle which is responsible for the contraction of the pupil, and another group of muscles known as the dilator muscles govern the expansion of the pupil. When you look at your iris in the mirror, you will notice a radiating pattern. This pattern is known as the trabecular meshwork. When Near Infrared Light (NIR) is flashed onto the iris, many unique features can be observed. These features include ridges, folds, freckles, furrows, arches, crypts, coronas, as well as other patterns which appear in various, discernable fashions.

Finally, the collaretta of the iris is the thickest region of it, which gives the iris its two distinct regions, known as the pupillary zone (this forms the boundary of the pupil), and the ciliary zone (which fills up the rest of the iris). Other unique features can also be seen in the collaretta region. The iris is deemed to be one of the most unique structures of human physiology, and in fact, each individual has a different iris structure in both eyes. In fact, even scientific studies have shown that even identical twins have different iris structures.

The idea of using the iris to confirm the identity of an individual dates all the way back to 1936, when an opthomolgist by the Frank Burch first proposed the idea. This idea was then patented in 1987, and by the mid nineties, Dr. John Daugmann of the University of Cambridge developed the first mathematical algorithms for it. Traditional iris recognition technology requires that the end user stand no more than ten inches away from the camera.

With the NIR light shined into the iris, various grayscale images are then captured, and then compiled into one primary composite photograph. Special software then removes any obstructions from the iris, which can include portions of the pupil, eyelashes, eyelids, and any resulting glare from the iris camera.

From this composite image, the unique features of the iris (as described before) are then “zoned off” into hundreds of phasors (also known as vectors), whose measurements and amplitude level are then extracted (using Gabor Wavelet mathematics), and then subsequently converted into a binary mathematical file, which is not greater than 500 bytes. Because of this very small template size, verification of an individual can occur in just less than one second.

From within the traditional iris recognition methods, this mathematical file then becomes the actual iris biometric template, which is also known as the “IrisCode”. However, in order to positively verify or identify an individual from the database, these iris based enrollment and verification templates (the IrisCode) must be first compared with one another. In order to accomplish this task, the IrisCodes are compared against one another byte by byte, looking for any dissimilarities amongst the string of binary digits.

In other words, to what percentage do the zeroes and the ones in the iris based enrollment and verification templates match up and do not match up against one another? This answer is found by using a technique known as “Hamming Distances”, which is even used in iris recognition algorithms of today.

After these distances are measured, tests of statistical independence are then carried out, using high level Boolean mathematics (such as Exclusive OR Operators [XOR] and Masked Operators). Finally, if the test of statistical independence is passed, the individual is then positively verified or identified, but if the tests of statistical independence are failed, then the person is NOT positively verified or identified.

The Market Applications of Iris Recognition

As a result of these of these technological breakthroughs in iris recognition, it now cuts across all realms of market applications. In the past decade, because of the monopolistic grip which held it, iris recognition served only a very limited number of market applications, and because of that, customer acceptance of it was very low, as well as the believability in the viability of this technology. Also, at that time, iris recognition technology was very expensive (about $3,000-$5,000), thus providing for a much bigger obstacle in its adoption rate. Today, the price has come down substantially, thus helping boost its acceptance by customers very quickly. Because of all of this, iris recognition has now become a dominant player in those market applications which were once traditionally held by hand geometry recognition and fingerprint recognition. These market applications include:

  1. Logical Access Entry: This deals with gaining access to servers and corporate networks and intranets;
  2. Physical Access Entry: This addresses issues of gaining access to secure areas in a facility or place of business;
  3. Time and Attendance: This deals with accurate time reporting and actual hours worked by employees;
  4. Critical Infrastructures: This includes nuclear power plants, oil refineries, large scale military installations, as well as government facilities;
  5. Airports: This includes everything from confirming a passenger’s identity as they make their through the security checkpoints to reading their e-Passports before they disembark at the country of their destination;
  6. Seaports: This involves all of the maritime activities which include securing marine terminals, and “high consequence” facilities such as oil and gas storage, chemical, intermodal and port operations;
  7. Military Checkpoints: This includes securing, with iris recognition, such areas as military bases, air force bases, and naval bases.

Iris Recognition: The Advantages & The Disadvantages

Iris recognition, when evaluated against the seven criterion, actually fares very well in terms of both acceptance and applicability for the markets it serves:

  1. Universality: In a general sense, everybody has at least one eye which can be scanned and the unique features extracted from, so literally, the technology can be used anywhere around the world. Even in the unfortunate chance that an individual is blind in one or both eyes, technically, the iris can still be scanned, even though it can be much more difficult for the iris recognition system to scan the actual image of the iris;
  2. Uniqueness: As mentioned, the iris, along with the retina, is one of the richest biometrics in terms of unique information and data. Even amongst identical twins, the irises are also unique. For example, Dr. John Daugmann, whom originally developed the iris recognition algorithms, calculated that the statistical probability of the iris being identical amongst twins is 1 in 10^78;
  3. Permanence: One of the biggest advantages of the iris is that it is very stable, and in fact, it hardly changes over the lifetime of an individual. Thus, in this regard, iris recognition does not possess the same flaws as facial recognition does. Also, the iris is considered to be an “internal” organ, thus it is not prone to the harsh conditions of the external environment, unlike the face, hand, or fingers. However, it should be noted that any direct, physical injury to the iris, or even an laser based vision corrective surgery will render the iris useless;
  4. Collectability: When compared to all of the other biometric technologies, the images of the iris are extremely easy to collect, both in terms of camera capture and the software analysis of the iris. In fact, the images of the iris can still be captured even when an individual is still wearing their eye glasses or contact lenses. The only disadvantage of iris recognition in this particular regard is that the image of the iris can be very much prone to blurring by the capture camera, and any excessive head tilts on the part of the individual can cause the iris image to be greatly distorted;
  5. Performance: Given the very small size of the iris recognition template, this technology appears to be extremely fast as well extremely accurate. For example, it possesses an FAR (False Acceptance Rate) level of .0001, and an FRR (False Rejection Rate) at a remarkable level of 0.0. As a result of these metrics, iris recognition works very well for identification based applications, as this is best exemplified by the iris recognition deployments in both Iraq and Afghanistan, where the technology is being used every day to identify hundreds of refugees in those particular countries;
  6. Acceptability: Because iris recognition is non contactless technology, overall, the acceptance has been pretty high. However initially, there can be some unease and fear of having one’s iris scanned. It should be noted that the NIR light used in iris recognition is not visible to humans, and there has been no physical harm cited as of yet to the eye, as a result of using iris recognition;
  7. Resistance to circumvention: Iris recognition technology is very difficult to spoof, because the system can discriminate a live iris from a fake iris by carefully examining the dilation and constriction of the pupil, and the use of encryption to further protect the iris recognition templates greatly prevents against reverse engineering.