Iris technology is an emerging research area, providing positive identification of an individual without contact or invasion, at extremely high confidencelevels. Iris scan has been developing an identification/verification system capable of positively identifying and verifying the identity of individuals without physical contact or human intervention. It is a new technology, using the unique patterns of the human iris, shows promise of overcoming previous shortcomings .
The video-based system locates the eye and iris; evaluates the degree of occlusion by eyelid and spectral reflection; determines the quality of image focus; and determines the center and boundary of the pupil and the limbus (outer edge of the iris) for processing. The iris is zoned, and the features therein measured and encoded into a 512-byte Iris Code for enrollment or identification. The presented biometric is compared to an extensive database for identification, or to a referenced Iris Code for verification. Computations and decisions are accomplished at extremely high rates of speed, resulting in processing times of less than two seconds.
The multiple features produce a non-duplicable organ with more than 400 degrees of freedom, or measurable variables.
of these to create a code which can be compared to an entire database in milliseconds, producing a positive identification with “imposter odds” as high as 1 in 1034.
In today’s information technology world, security for systems is becoming more and more important. The number of systems that have been compromised is ever increasing and authentication plays a major role as a first line of defense against intruders. he three main types of authentication are something you know (such as a password), something you have (such as a card or token), and something you are (biometric).
and identification, as they are difficult to replicate and steal. If biometrics is used in conjunction with something you know, then this achieves what is known as two-factor authentication. both components before a user is able to access anything. Biometric identification utilizes physiological and behavioral characteristics to authenticate a person’s identity. Some common physical characteristics that may be used for identification include fingerprints, palm prints, hand geometry and iris patterns.
Iris Recognition Process
The process of capturing an iris into a biometric template is made up of 3 steps:
1. Capturing the image
2. Defining the location of the iris and optimizing the image
3. Storing and comparing the image.
1.Capturing the Image
The image of the iris can be captured
using a standard camera using both visible and infrared light and may be either a manual or automated procedure. one meter to capture the image. In the manual procedure, the user needs to adjust the camera to get the iris in focus and needs to be within six to twelve inches of the camera.
2. Defining the Location of the Iris and Optimizing the Image
Once the camera has located the eye, the iris recognition system then identifies the image that has the best focus and clarity of the iris.
The iris recognition system then identifies the areas of the iris image that are suitable for feature extraction and analysis. This involves removing areas that are covered by the eyelids, any deep Shadows and reflective areas. The following diagram shows the optimization of the image.
3. Storing and Comparing the Image
Once the image has been captured, “an algorithm uses 2-D Gabor wavelets to filter and map segments of the iris into hundreds of vectors (known here as phasors)”9. The 2-D Gabor phasor is simply the “what” and “where” of the image. Even after applying the algorithms to the iris image there are still 173 degrees of freedom to identify the iris.
These algorithms also take into account the changes that can occur with an iris, for example the pupil’s expansion and contraction in response to light will stretch and skew the iris. This information is used to produce what is known as the Iris Code, which is a 512byte record. .
The comparison also doesn’t actually compare the image of the iris but rather compares the hexadecimal value produce the Hamming Distance is a measure of the variation between the Iris Code record for the current iris and the Iris Code records stored in the database., i.e. bit 1 from the current Iris Code and bit 1 from the stored Iris Code record are compared, then bit 2 and so on. Any bits that don’t match are assigned a value of one and bits that do match a value of zero.
Once all the bits have been compared, the number of non-matching bits is divided by the total number of bits to produce a two-digit figure of how the two Iris Code records differ. For example a Hamming Distance of 0.20 means that the two Iris Code differ by 20%. With all biometric systems there are two error rates that need to be taken into consideration.
Advantages of Iris Recognition Technology
The physiological properties of irises are major advantages to using them as a method of authentication. As discussed earlier, the morphogenesis of the iris that occurs during the seventh month of gestation results in the uniqueness of the iris even between multi-birth children. These patterns remain stable throughout life and are protected by the body’s own mechanisms. This randomness in irises makes them very difficult to forge and hence imitate the actual person.
In addition to the physiological benefits, iris-scanning technology is not very
intrusive as there is no direct contact between the subject and the camera technology. It is noninvasive, as it does not use any laser technology, just simple video technology. The camera does not record an image unless the user actually engages it.
It poses no difficulty in enrolling people that wear glasses or contact lenses. In addition to the physiological benefits, iris-scanning technology is not very intrusive as there is no
direct contact between the subject and the camera technology., just simple video technology. The physiological properties of irises are major advantages to using them as a method of authentication. As discussed earlier, the morphogenesis of the iris that occurs during the seventh month of gestation results in the uniqueness of the iris even between multi-birth children
The accurateness of the scanning technology is a major benefit with error rates being very low, hence resulting in a highly reliable system for authentication. Scalability and speed of the technology are a major advantage. The technology is designed to be used with large-scale applications such as with ATMs. The speed of the database iris records are stored in is very important. Users do not like spending a lot of time being authenticated and the ability of the system to scan and compare the iris within a matter of
minutes is a major benefit.
The need for secure methods of authentication is becoming increasingly important in the corporate world today. Passwords, token cards and PINs are all risks to the security of an organization due to human nature. Our inability to remember complex passwords and tendency to write these down along with losing token cards or forgetting PINs all contribute to the possible breakdown in security for an organization. The uniqueness of the iris and low