False Accept Rate (FAR) is a statistical measure used to determine the probability of a biometric security system allowing unauthorized user access. It measures the percentage of invalid inputs which are incorrectly accepted. It is sometimes denoted as a False Match Rate (FMR).
FAR is expressed as the ratio of the number of false acceptances to the number of identification attempts, indicating the proportion of verification transactions where wrongful identity claims are mistakenly confirmed. FAR is a crucial metric in assessing the precision and effectiveness of biometric security systems such as facial recognition software or fingerprint scanners. A lower FAR value signifies a more reliable system, while a higher FAR value indicates a higher risk of unauthorized access.
The False Reject Rate (FRR) and False Accept Rate (FAR) are two important measures used to gauge the accuracy of biometric identification systems. While the FRR measures the frequency with which a legitimate user is wrongly rejected by the system, the FAR measures the frequency with which an imposter is wrongly accepted by the system. Put simply, the FRR indicates how well the system can recognize authorized users, while the FAR indicates how well the system can reject unauthorized users. The False Accept Rate (FAR) and False Reject Rate (FRR) are interrelated in a way that if one metric is decreased, the other will increase. While minimizing the FAR is crucial for ensuring system security by preventing unauthorized access, the FRR affects the user experience by determining how often legitimate users are denied access. Achieving the right balance between usability and security depends on the specific context and intended use of the system