Biometrics is the automated method of recognizing a person based on a physiological or behavioral characteristic. Biometric technologies are becoming the foundation of an extensive array of highly secure identification and personal verification solutions.
Biometric technologies should be considered and evaluated giving full consideration to the following characteristics:
- Universality: Every person should have the characteristic. People who are mute or without a fingerprint will need to be accommodated in some way.
- Uniqueness: Generally, no two people have identical characteristics. However, identical twins are hard to distinguish.
- Permanence: The characteristics should not vary with time. A person’s face, for example, may change with age.
- Collectibility: The characteristics must be easily collectible and measurable.
- Performance: The method must deliver accurate results under varied environmental circumstances.
- Acceptability: The general public must accept the sample collection routines. Nonintrusive methods are more acceptable.
- Circumvention: The technology should be difficult to deceive.
Fingerprint Identification is the method of identification using the impressions made by the minute ridge formations or patterns found on the fingertips. No two persons have exactly the same arrangement of ridge patterns, and the patterns of any one individual remain unchanged throughout life. Fingerprints offer an infallible means of personal identification. Other personal characteristics may change, but fingerprints do not.
Face Recognition Systems
Most face recognition systems focus on specific features on the face and make a two-dimensional map of the face. Newer systems make three-dimensional maps. The systems capture facial images from video cameras and generate templates that are stored and used for comparisons. Face recognition is a fairly young technology compared with other biometrics like fingerprints.
One face recognition technology, referred to as local feature analysis, looks at specific parts of the face that do not change significantly over time, such as:
- Upper sections of eye sockets
- Area surrounding cheek bones
- Sides of mouth
- Distance between eyes.
Data such as the distance between the eyes, the length of the nose, or the angle of the chin contribute collectively to the template.
A second method of face recognition is called the eigenface method. It looks at the face as a whole. A collection of face images is used to generate a two-dimensional gray-scale image to produce the biometric template.
Retina and Iris Identification
Iris recognition today combines technologies from several fields including, computer vision (CV), pattern recognition, statistical interference, and optics. The goal of the technology is near-instant, highly accurate recognition of a person’s identity based on a digitally represented image of the scanned eye. The technology is based upon the fact that no two iris patterns are alike (the probability is higher than that of fingerprints). The iris is a protected organ which makes the identification possibilities life long. The iris can therefore serve as a life long password which the person must never remember. Confidence in recognition and identification facilitates exhustive searches through nation-sized databases.
Iris recognition technology looks at the unique characteristics of the iris, the colored area surrounding the pupil. While most biometrics have 13 to 60 distinct characteristics, the iris is said to have 266 unique spots. Each eye is believed to be unique and remain stable over time and across environments (e.g., weather, climate, occupational differences).
Iris recognition systems use small, high-quality cameras to capture a black and white high-resolution photograph of the iris. 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. This type of biometric scanning works with glasses and contact lenses in place. Therefore, iris scan biometrics may be more useful for higher risk interactions, such as building access.