21-01-2013, 04:40 PM
BIOMETRICS TECHNOLOGY
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INTRODUCTION
BIOMETRICS refers to the automatic identification of a person based on his physiological / behavioral characteristics. This method of identification is preferred for various reasons;the person to be identified is required to be physically present at the point of identification; identification based on biometric techniques obviates the need to remember a password or carry a token. With the increased use of computers or vehicles of information technology, it is necessary to restrict access to sensitive or personal data. By replacing PINs, biometric techniques can potentially prevent unauthorized access to fraudulent use of ATMs, cellular phones, smart cards, desktop PCs, workstations, and computer networks. PINs and passwords may be forgotten, and token based methods of identification like passports and driver’s licenses may be forged, stolen, or lost .Thus biometric systems of identification are enjoying a renewed interest. Various types of biometric systems are being used for real–time identification ; the most popular are based on face recognition and fingerprint matching. However there are other biometric systems that utilize iris and retinal scan, speech, facial thermo grams, and hand geometry.
ORIGIN OF BIOMETRICS
Biometrics dates back to the ancient Egyptians, who measured people to identity them. But automated devices appeared within living memory. One of the first commercial devices introduced less than 30 years ago. The system is called the indentimat . The machine measured finger length and installed in a time keeping system. Biometrics is also catching on computer and communication system as well as automated teller machines (ATM’s).
Biometrics devices have three primary components. One is an automated mechanism that scans and captures a digital / analog image of a living personal characteristics. Another handles compression, processing, storage and comparison of image with the stored data . The third interfaces with application systems. These pieces may be configured to suit different situations . A common issue is where the stored image resides:on a card, presented by the person being verified or at a host computer.
TYPOLOGY OF BIOMETRICS
Biometrics encompasses both physiological and behavioural characteristics. This is illustrated in Figure 1. A physiological characteristic is a relatively stable physical feature such as finger print, hand silhouette , iris pattern or facial features. These factors are basically unalterable with out trauma to the individual.
A behavioral tract, on the other hand, has some physiological basis, but also reflects person’s physiological makeup. The most common trait used in identification is a person’s signature. Other behaviours used include a person’s keyboard typing and speech patterns. Because of most behavioural characteristics change over time, many biometrics machine not rely on behavior. It is required to update their enrolled reference template may differ significantly from the original data, and the machine become more proficient at identifying the person. Behavioral biometrics work best with regular use.
VARIOUS BIOMETRIC SYSTEMS
HAND
The three dimensional shape of a person’s hand has several advantages as an identification device. Scanning a hand and producing a result takes 1.2 seconds. It requires little space for data storage about 9 bytes which can fit easily magnetic strip credit cards.Hand geometry is the grand daddy of biometrics by virtue of its 20 year old history of live application. Over this span six hand-scan products have been developed but one commercially viable product currently available, the ID3D hand key is given below. This device was developed by Recognition Systems Inc.
The user keys, in an identification code, is then positions his or her and on a plate between a set of guidance pins. Looking down upon the hand is a charge-coupled device (CCD) digital camera, which with the help of mirror captures the side and top view of the hand simultaneously.
EYE
The other method of identification involves the eye. Two types of eye identification are possible, scanning the blood vessel pattern on the retina and examining the pattern of the structure of the iris. Now we can look through a detailed description of each type below.
RETINA
Retina scans, in which a weak infrared light is directed through the pupil to the back of the eye, have been commercially available since 1985. The retinal pattern is reflected back to a charge-coupled device (CCD) Camera, which captures the unique pattern and represents it in less than 35 bytes of information. Retina scans are one of the best biometrics performers on the market, with low false reject rates and nearly 0 present false accept rate. The technology also offers small data templates provides quick identity confirmations, and handles well the job of recognizing individuals in a database of under 500 people. The toughest hurdle for retinal scan technology is user resistance. People don’t want to put their eye as close to the device as necessary. Only one company, Eyedentyfy Inc., produces retinal scan products.
IRIS
Once it was the whites of their eyes that counted. Retinal pattern recognition has been tried but found uncomfortable because the individual must touch or remain very close to a retinal scanner. Now the iris is the focus of a relatively new biometrics means of identification. Standard monochrome video or photographic technology in combination with robust software and standard video imaging techniques can accept or reject an iris at distance of 30-45 cm.