Biometric systems

An image showing an iris.Biometric systems use biological traits or behavioural characteristics to identify or verify an individual.

Because the other methods people use to identify themselves are variable and can easily be lost, stolen or replicated, biometric systems are being developed to bring tighter security and improve identification. A biometric can be hard to steal or replicate.

Currently, the common biometric systems deal with:

In considering biometrics, it is important to distinguish the difference between 'identifying' who a person is and 'verifying' a person.


Involves confirming or denying an individual’s claimed identity - Is this person the same as the person to whom the card or token was issued?


Involves checking an individual’s identity against a large database - Who is this person?

Resolving these questions using biometrics can significantly increase security at airports or at cash machines, help limit the use of stolen items such as mobile phones, stop people obtaining items using a false identity and expose people with multiple or fake identities.

Photograph showing a fingerprint and the words security.In areas such as security, especially where large numbers of people need to be managed and controlled, biometric systems can not only greatly improve security and access control, they can also improve speed of throughput. Well designed biometric systems should also reduce manpower costs or release security staff to do more important work.

Biometrics are also being developed to help reduce fraud and fake identities on the Internet. If personal data transactions on the web can be more secure using biometrics, this will increase confidence in how information and data is stored and accessed.

One of the advantages of biometric systems is that there is no need for a PIN number or password to be remembered; this would help many people with dyslexia. A mobile phone could be protected by fingerprint recognition; this would benefit those people who are particularly at risk of having their phone stolen.

Hand or finger geometry

Fingerprint systems are working well, in that they have a low number of false acceptances. However, they can be problematic for those with damaged fingers or with prosthetic hands. Some users will associate fingerprints with criminal investigations, so may be reluctant to use the system.

Facial recognition

Facial recognition can have an unacceptable level of either false positives or false negatives. It is technically best used to verify a person rather than identify who a person is. Thus it is an appropriate technology when used with a secure token such as a smart card. From the user’s perspective it's non-intrusive nature is a major advantage and users are likely to accept such a system if it can provide a decision quickly, and is seen to be protecting their interests.

Photograph of an iris scanner being used.

Voice recognition

Voice recognition may not cause many problems for people with disabilities but the reliability of this system can be easily influenced by changes in a voice due to a sore throat or common cold. People who are deaf may speak in ways that are difficult to match.

Iris or retina recognition

Iris recognition is a secure system, but the user has to position their eye in relation to a camera. This can give problems for users who are very tall, very short, or in a wheelchair. There are obvious problems for users who are blind or have a visual prosthesis. In addition some ethnic and religious groups may consider such a system unacceptable.

Go to Biometric Systems Guidelines

Last updated: 06.08.2009   © Copyright reserved    Website design: Digital Accessibility Team