Biometrics Overview

Biometrics is the use of physiological or behavioral characteristics to determine or verify an individual’s identity.

 

Description

Physiological biometrics are based on data derived from direct measurements of a part of the human body. Fingerprints, iris-scans, retina-scans, hand geometry, and facial recognition are all leading physiological biometrics.

 

Behavioral characteristics are based on an action taken by a person. Behavioral biometrics, in turn, are based on measurements and data derived from an action, and indirectly measure characteristics of the human body. Voice recognition, keystroke-scans, and signature-scans are leading behavioral biometric technologies. One of the defining characteristics of a behavioral biometric is the incorporation of time as a metric - the measured behavior has a beginning, middle and end.

 

A key point is that while behavioral biometrics are based on an individual’s actions, those actions are in turn influenced by physiological attributes such as the size of a person’s hand (signature-scan) or the shape of their vocal chords (voice recognition).

 

Process

All biometrics follow the same general process of enrollment, comparison and identification. The particular biometric component must first be enrolled in order to extract the unique identifying features which in turn are used in the creation of a biometric template. The biometric template will then be used during a real-time comparison of a presented biometric in determining a successful match. Matching occurs via a machine-based mathematical algorithm of feature extraction and template comparison. The result is that biometric decision-making is very rapid, and in most cases a match/non-match decision occurs in one second or less.

 

Comparing Biometrics

Biometrics are most frequently compared based on several factors including:

  • Universality – how commonly a biometric is found in each individual
  • Uniqueness – how well the biometric separates one individual from another
  • Permanence – how well a biometric resists aging

 

Biometric Technologies or Systems are often compared by:

  • Intrusiveness – how easy it is to acquire a biometric for measurement with minimal user interaction
  • Reliability – typically measured by the False Reject Rate, or the rate at which an enrolled user is not accurately identified
  • Security – typically measured by the False Accept Rate, or the rate at which an individual is incorrectly matched to an enrolled individual
  • Ease of Use – indicating the time and general use model by an individual interacting with a biometric system
  • Circumvention – the ability to fool or ‘spoof’ a biometric system with an non-genuine biometric sample
  • Integration – the general set of factors which are involved with integrating a biometric technology, such as the biometric capture device’s size, cost, power requirements, and other physical or technical attributes.

 

Uses

Biometrics are used for one of two purposes; identification or authentication. Identification pertains to 1:Many matching of an unknown individual against a typically large database of known individuals. Authentication involves 1:1 or 1:Few matching and is used to verify that a person is a registered or authorized user.

 

While no one biometric technology is perfect for all situations, certain biometric technologies will be ideally suited for specific applications based on factors such as security, ease of use and cost.