FAR

In biometrics, the rate at which unauthorized users are wrongly accepted.

FAR measures how often a biometric system incorrectly accepts an unauthorized person as a legitimate user, making it a direct security risk because it represents false positives that grant improper access. It is governed by the matching threshold, and loosening that threshold to reduce user frustration raises the FAR. The exam pairs it with FRR, the rate of wrongly rejecting valid users, and with the CER, the crossover point where the two rates are equal and which serves as a common accuracy benchmark for comparing systems.