False acceptance ratio definition
False acceptance ratio (FAR) is a biometric security metric that measures the rate at which a biometric authentication system incorrectly accepts an unauthorized user’s attempt as valid. In simpler terms, FAR represents the likelihood that the system will mistakenly grant access to someone who should not have access. A lower FAR indicates better security — the system is less likely to incorrectly accept unauthorized users.
See also: biometric authentication
How FAR is calculated
The False Acceptance Ratio (FAR) in a biometric authentication system can be calculated using the following formula:
- FAR = (Number of False Acceptances / Total Number of Impostor Attempts) * 100
Real-world applications of FAR
- Airport security. Biometric systems, such as fingerprint or facial recognition, are used at airports to verify the identity of travelers. A high FAR could potentially mean unauthorized people are boarding flights.
- Smartphones and tablets. Many smartphones now incorporate biometric authentication for unlocking devices (e.g., fingerprint or facial recognition). A high FAR could allow unauthorized users to access personal information.
- Healthcare records. Biometric systems are used to secure access to electronic health records (EHRs). A high FAR in healthcare could lead to unauthorized access to patient information.
- Financial services. Some banks and financial institutions use biometric authentication for online banking or ATM transactions. A significant FAR could lead to fraudulent access to bank accounts and financial transactions.
- Government ID programs. In government identification programs, like national ID cards or passports, biometrics are used to verify identity. A high FAR could lead to governments issuing identity documents to unauthorized individuals.