Biometrics

What biometrics are

Biometrics authenticate a user by measuring a physical or behavioural characteristic that is unique to that person, such as the shape of an ear. You present the characteristic to a scanner, which compares it with a stored template. If the two match, access is granted.

Benefits and drawbacks for the user

Biometrics can be quick, because there is no password to remember and no card to carry. But a scan can fail to recognise a genuine user, which is called a false negative. This can happen because of physical changes, such as a cut, swelling or a bandage covering the characteristic, or because the user's head is not in the right position.

Some scanners need you to touch a pad or rest your hand on a surface, and a surface used by lots of people can pass on germs, so these scanners can be unhygienic.

Cost, setup and data risks

Biometrics can be expensive to buy, set up, install, maintain and repair because they need specialist equipment and expert work. Setting up is time-consuming, as every authorised user must be enrolled: their biometric data is recorded as a template before they can use the system. For example, a bakery chain uses ear-shape scanners to unlock its tills. Staff save time at the start of a shift, but the scanners cost more than keypads, a new baker must be enrolled before their first shift, and a broken scanner can leave a till out of action until it is fixed. If biometric data is compromised it cannot be changed like a password, and stolen data could be used to access other systems. Some people are also uneasy about a computer keeping a record of their biometrics.