How it works...

All biometric systems operate in a similar fashion. First, the system captures a sample of the biometric characteristic (this is known as the enrollment process). During enrollment, some biometric systems may require a number of samples in order to build a profile of the biometric characteristic. Unique features are then extracted and converted by the system into a mathematical code. This sample is then stored as the biometric template for the enrollee. The template can reside on a computer database, smart card or barcode. 

In addition, the biometric system may require a trigger, or a means of matching the template to the person, for e.g. a PIN is keyed-in to access the template, or a smart card storing the template is inserted into a card reader. In either case, the end user interacts with the biometric system for a second time to have his or her identity checked. A new biometric sample is then taken and this is compared with the template. If the template and the new sample match, the end user is granted access. This is the basic premise of biometrics - that a person has a sample of their biometric data captured and the biometric system decides if it matches with another sample.

The following four-stage process illustrates the way biometric systems operate:

• Capture-
  physical or behavioral sample is captured by the system during enrollment
• Extraction-
  unique data is extracted from the sample and a template is created
• Comparison-
  the template is then compared with a new sample
• Matching-
  the system then decides if the features extracted from the new sample are matching or not