Biometrics is usually associated with fingerprints and their cataloging, but it is applicable where any physical, psychological or even behavioral trait can be available for authentication. These traits are the identifiers; and they are usually categorized into the physical or the behavioral. The physical identifiers include the hand (palm veins, palm print and hand geometry), the eye (iris or retina recognition), overall face recognition, fingerprints, as well as DNA and the body scent. The behavioral identifiers refer to the voice, the way of walking (gait) and other activities including typing.
There are many different ways of using biometrics, many of which are featured in products of popular culture such as television shows, movies or comic strips, but in reality as well (mostly through the fingerprint). A personal possession like a secure armory, for example, may have biometrics applied, as can be seen at http://www.gunsafecritic.com – best biometric gun safe, though many biometrics devices would be for public usage.
Some countries have combined biometrics with their system of ID cards and/or passports; some are more intent on border control while others apply a very general identification process on their people. Australia links every visitor to his or her passport, and Canada’s concerns are similar in that it tries to control its borders through biometrics. Brazil has several features mandatorily included in every citizen’s ID card, and South Korea has one fingerprint per ID card. Germany has issued the ePass to its citizens, which includes a digital photo and one fingerprint, both put into a chip; iris scanning is another measure that is said to be added. Germany requires temporary residents, if their stay is long enough, to be subjected to some kind of identification using biometrics. It has also applied biometrics to its athletes for the Olympic games, by providing them with ID cards that allowed them to enter a secure building.
The largest biometrics data, however, is Indian, and includes fingerprints, iris scans and facial images along with detailed demographic data. The Indian government is said to have over 500 million of such data, which is ever increasing. Indians can vote or get public service, such as rations, from anywhere in the country.
For such a vast application of biometrics, within and across countries, the choice of identifiers is extremely important. A study has pointed out that there are seven standards of assessing the suitability of an identifier: the universality, uniqueness, permanence, (the convenience of) measurability, (the degree of) performance (of related technologies), acceptability (by people) and (the possibility of) circumvention (by faking).
In movies there have been many instances of using biometrics to stop or allow a person’s entrance or exit. Some may remember Demolition Man, in which the opening of a locked door using iris images was managed by taking out the villain’s eye from his corpse, though of course in reality an eye that’s been taken out would not work to achieve such a purpose. In reality, no biometrics system is perfect, and to make up for its weaknesses, a system could be multimodal, meaning it scans or identifies more than one feature. They are ever evolving and ever more applied to more areas of the human life.