Biometrics in Authentication

There are three factors of authentication:

• Something you know (such as a password or PIN)
• Something you have (such as a smart card)
• Something you are (using biometrics)

Biometrics can be very exact when the technology is implemented accurately. However, it is possible to get false readings. 

Two possible false readings are:

• False acceptance. This is when a biometric system incorrectly identifies an unauthorized user as an authorized user.
• False rejection. This is when a biometric system incorrectly rejects an authorized user.

True readings occur when the biometric system indicates a match.

Two possible readings are:

• True acceptance. The biometric system accurately determines a positive match.
• True rejection. The biometric system accurately determines a non-match.