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The word “biometrics” is derived from the Greek words ‘bios’ and ‘metric’; which means life and measurement respectively. This directly translates into “life measurement”.

Biometrics is a field of security and identification technology based on the measurement of unique physical characteristics such as fingerprints, retinal patterns, and facial structure.

To verify an individual’s identity, biometric devices scan certain characteristics and compare them with a stored entry in a computer database.

While the technology goes back years and has been used in highly sensitive institutions such as defense and nuclear facilities, the proliferation of electronic data exchange generated new demand for biometric applications that can secure electronically stored data and online transactions.

Biometrics technologies measure a particular set of a person’s vital statistics in order to determine identity.

In the most contemporary computer science applications, the term “life measurement” adapts a slightly different role. Biometrics in the high technology sector refers to a particular class of identification technologies.

These technologies use an individual’s unique biological traits to determine one’s identity. The traits that are considered include fingerprints, retina and iris patterns, facial characteristics and many more.

Biometrics is a general term used alternatively to describe a characteristic or a process in biometric identification systems.

As a Characteristic: A measurable biological (anatomical and physiological) and behavioural characteristic that can be used for automated recognition.

As a Process: Automated methods of recognizing an individual based on measurable biological (anatomical and physiological) and behavioural characteristics.


It is possible to understand if a human characteristic can be used for biometrics in terms of the following parameters:

v   Universality: each person should have the characteristic

v   Uniqueness: is how well the biometric separates individually from another.

v   Permanence: measures how well a biometric resists aging.

v   Collectability: ease of acquisition for measurement.

v   Performance: accuracy, speed, and robustness of technology used.

v   Acceptability: degree of approval of a technology.

v   Circumvention: ease of use of a substitute.


Fingerprints: Fingerprint-based biometric systems scan the dimensions, patterns, and topography of fingers, thumbs, and palms.

The most common biometric in forensic and governmental databases, fingerprints contain up to 60 possibilities for minute variation, and extremely large and increasingly integrated networks of these stored databases already exist.

The largest of these is the Federal Bureau of Investigation’s (FBI) Automated Fingerprint Identification System, with more than 630 million fingerprint images.

Facial Recogntion: Facial recognition systems vary according to the features they measure. Some look at the shadow patterns under a set lighting pattern, while others scan heat patterns or thermal images using an infrared camera that illuminates the eyes and cheekbones.

These systems are powerful enough to scope out the minutest differences in facial patterns, even between identical twins. The hardware for facial recognition systems is relatively inexpensive, and is increasingly installed in computer monitors.

Eye Scans: There are two main features of the eye that are targeted by biometric systems: the retina and the iris. Each contains more points of identification than a fingerprint.

Retina scanners trace the pattern of blood cells behind the retina by quickly flashing an infrared light into the eye. Iris scanners create a unique biological bar code by scanning the eye’s distinctive color patterns.

Eye scans tend to occupy less space in a computer and thus operate relatively quickly, although some users are squeamish about having beams of light shot into their eyes.

Voice Verification: Although voices can sound similar and can be consciously altered, the topography of the mouth, teeth, and vocal cords produces distinct pitch, cadence, tone, and dynamics that give away would-be impersonators.

Widely used in phone-based identification systems, voice-verification biometrics also is used with personal computers.

Hand Geometry: Hand-geometry biometric systems take two infrared photographs-one from the side and one from above-of an individual’s hand.

These images measure up to 90 different characteristics, such as height, width, thickness, finger shape, and joint positions and compare them with stored data.

Keystroke Dynamics: A biometric system that is tailor-made for personal computers, keystroke-dynamic biometrics measures unique patterns in the way an individual uses a keyboard-such as speed, force, the variation of force on different parts of the keyboard, and multiple-key functions-and exploits them as a means of identification.


There are basically two types of biometrics:

  1. Behavioral Biometrics
  2. Physical Biometrics

(1) Behavioural Biometric Definition: Behavioural biometrics basically measures the characteristics which are acquired naturally over a time. It is generally used for verification.

Examples of Behavioural Biometrics Include

  •          Speaker Recognition – analyzing vocal behaviour
  •          Signature – analyzing signature dynamics
  •          Keystroke – measuring the time spacing of typed words

(2) Physical Biometric Definition: Physical biometrics measures the inherent physical characteristics on an individual. It can be used for either identification or verification.

  •       Examples of Physical Biometrics Include
  •          Bertillonage – measuring body lengths (no longer used)
  •          Fingerprint – analyzing fingertip patterns
  •          Facial Recognition – measuring facial characteristics
  •          Hand Geometry – measuring the shape of the hand
  •          Iris Scan – analyzing features of colored ring of the eye
  •          Retinal Scan – analyzing blood vessels in the eye
  •          Vascular Patterns – analyzing vein patterns
  •          DNA – analyzing genetic makeup

Some Leading Edge Applications

  •          Fingerprint scanners (and the necessary software to store and compare fingerprints) have already been installed in                 laptop computers and PDAs like the iPaq.
  •          Sensors installed in automobiles can identify the driver, and adjust mirrors, seat positions and climate controls.
  •          Special readers can measure various elements of hand geometry, comparing the result with data on file for each person
  •          Surveillance cameras can search crowds for missing persons or criminal suspects.
  •          Face recognition software can be modified to recognize gestures, leading to improved assistive technologies for quadriplegic patients



There are two main modules in a biometrics system, “storing” and “comparing”. The systems must first store your information before it can use this stored information to compare and verify. The storing process however differs between different systems.

For instance, if the biometrics system uses thumb impression as the mode of verification, then your thumb impression will be first captured in film and stored in the biometrics database system. Instead of storing as it is, the system will compress and store it.

If for instance your face is used as the mode of verification, then your face will be photographed in different angles and stored in the biometrics database systems. The same goes for voice recording and eyes mode of verification.

Once this storing process is done, the ‘comparing’ process is done daily or as and when required. For example let us assume that your company uses fingerprint biometrics systems. When you come to office daily, there will be a fingerprint reader at the entrance. You will have to put your finger on this fingerprint reader which will capture your fingerprint and send to the biometrics system. The biometrics system will then ‘compare’ this fingerprint to the fingerprint that was previously stored in the database. If both of them match then you are authenticated.

Advantages of a Biometrics System

The fact that you will have to personally be present in order to authenticate yourself is the advantage of this system. Fingerprint or retina of the eyes of one person does not match with anyone else’s data in the database. Therefore there is absolutely no chance of other people using your identity.

Disadvantages of a Biometric System

  •   The fingerprint of those people working in Chemical industries are often affected. Therefore these companies should not use the fingerprint mode of authentication.
  •   It is found that with age, the voice of a person differs. Also when the person has a flu or throat infection the voice changes or if there are too much noise in the environment this method may not authenticate correctly. Therefore this method of verification is not workable all the time.
  • For people affected with diabetes, the eyes get affected resulting in differences.
  • Biometrics is an expensive security solution.