A Biometric System is a system for the automated recognition of individuals based on their behavioural and biological characteristics.
Fingerprints, face geometry, iris patterns and hand geometry are examples of biological characteristics, while dynamic signature recognition (the way in which a signature is written rather than the resulting graphic) is an example of a behavioural characteristic. In reality, most biometric characteristics comprise elements of both biology and behaviour.
Speaker recognition for example, depends on biological factors such as the shape of the vocal tract as well as behavioural influences such as the region of upbringing. Conversely, biological characteristics such as fingerprints are affected by behaviour when placing a finger onto a sensor.
Biological and behavioural characteristics of an individual are those that can be detected and from which distinguishing repeatable biometric features can be extracted for the purpose of automated recognition of individuals.
Biological and behavioural characteristics are physical properties of body parts, physiological and behavioural processes created by the body and combinations of any of these. Distinguishing does not necessarily imply individualization.
Wherever there is a need to identify or verify a human being there is a potential application for biometrics. This includes entry control to buildings and secure areas including countries, as well as logical access control to resources such as bank accounts and entitlement services.
Traditional methods to secure such applications include magnetic and smart cards, tokens as well as passwords and PINs. However, when it comes to identity assurance, biometric technologies have an unsurpassed advantage: they are intrinsically linked to the person.
As the number and scale of deployments of biometric recognition systems increase, biometrics is moving from an era where vendor-specific products, techniques and solutions were acceptable, into an era where interoperability is important and conformance to standards is required by most procurers of biometric products.
Unlike the use of other forms of authentication, such as passwords or tokens, biometric recognition provides a strong link between an individual and a claimed identity. One area where biometrics can provide substantial help is in guarding against attempts to establish fraudulent multiple identities or prevent identity fraud. By searching through the stored references, individuals who appear to have previously enrolled using a different identity can be highlighted for further investigation. It is very difficult to perform this type of check without the use of biometrics. What constitutes a good biometric system is not a simple question because the answer depends greatly on the requirements of the application. Desirable factors include:
Currently, national-scale applications, such as the national identity scheme, are prominent. Biometric passports, visas and other border control programmes are increasingly using biometrics to address major concerns of impersonation and multiple identities. By supplementing existing document checks with biometrics, it is believed that instances of identify fraud in international travel can be substantially reduced.
In the commercial sector, biometric recognition is typically used for physical access control to buildings and logical access control to IT systems. Financial institutions are making increasing use of speaker recognition systems for remote identification of customers telephoning call centres. Advantages include convenience to customers (no need to remember passwords), increased security and accountability, and lower administration costs.
For biometric applications to be effective, high quality registration and enrolment processes must be in place to establish the correct identity of the individuals being registered, their entitlement to be registered, and to generate high quality biometric references that will facilitate reliable recognition in the future.
Interoperability is also very important for biometrics. Large-scale multi-nation programmes such as biometric passports, require systems provided by different vendors to interoperate. This necessitates common specifications for biometric data formats, quality and performance, and corresponding conformance tests. The development of these specifications lies at the heart of biometric standards.