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False rejection

False rejection definition

A false rejection is when an authentication system denies access to someone who should be allowed in. It happens when the system fails to recognize or authenticate an authorized person or a legitimate action.

See also: False acceptance ratio, biometric authentication

Why does a false rejection happen?

Bad quality inputs: Like a smudged fingerprint on a laptop or a blurry face when opening a phone.

User changes: The person grew a new beard, or their voice is a little hoarse, so the system can't recognize it.

System limitations: It happens because of software issues, algorithmic limitations, or hardware inadequacies.

A short history of false rejections:

Early days. Initially, security relied on keys, passwords, or PINs. False rejections meant forgotten passwords or lost keys.

Biometrics. In the late 20th century, biometric systems entered the field, especially in high-security areas. Early versions had way higher rates of false rejections because the technology was less advanced.

Technological improvements. As biometric technology improved, the accuracy increased. But so did the complexity of false rejections. A user can be denied access because their biometric data has changed.

AI and machine learning. Integration of AI has improved biometrics, but the challenge persists in high-security environments.