Biometric Authentication

Biometric authentication checks who you are by measuring a physical characteristic of your body. A sensor takes a fresh reading and compares it with a stored copy of that characteristic. If the two are close enough to match, your identity is verified and you are allowed in.

Because a biometric belongs to you, there is no password to forget or card to lose, and it is harder to share than a password.

Common methods

Method	What is measured	Typical use
Fingerprint	The ridges and whorls on a fingertip	Unlocking a phone or clocking in at work
Facial recognition	Distances between features such as the eyes, nose and jaw	Unlocking a laptop or passing through an airport gate
Retinal scan	The pattern of blood vessels at the back of the eye	A high-security door into a room holding servers
Palm vein recognition	The vein pattern beneath the skin of the palm	Opening a bank vault or using a cash machine
Ear recognition	The shape and ridges of the outer ear	Specialist identity checks
Voice recognition	The sound and pattern of a person speaking	Confirming identity during a phone call to a bank

For example, a leisure centre could fit a gate that reads the vein pattern in a member's palm, so members enter without carrying a card that could be lost or handed to a friend.

Biometrics are not foolproof. A photograph may trick a simple facial recognition camera, and a recording may trick voice recognition, so high-value systems often combine a biometric with a password or PIN. Biometric systems can also reject the correct person, for instance when a finger is cut or a voice is croaky from a cold.

Common methods

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