3FA

Three-factor authentication (3FA) is an authentication method that requires three independent forms of evidence to verify a user’s identity. It represents a stricter approach than two-factor authentication (2FA) and is intended to reduce the risk of unauthorized access if any single factor is compromised.

The three factors commonly fall into three categories: something the user knows (such as a password or PIN), something the user has (a physical device like a security token, smart card, or a mobile device capable of generating codes), and something the user is (a biometric trait such as a fingerprint, facial recognition, or iris scan). Implementations may combine these in various ways, for example a password plus a hardware token plus a biometric check, or a password plus a biometric check plus a secondary device confirmation.

3FA is often used in high-security environments where the cost of a breach is substantial, including financial services, government systems, and sensitive enterprise networks. It can offer stronger protection than 2FA, but it also introduces greater complexity, potential usability friction, and administrative overhead. Enrollment of biometrics, management of hardware tokens, and consistent device compatibility are common considerations.

Security and reliability considerations include the possibility of all three factors being compromised or spoofed, the handling and protection of biometric data, and the impact of false rejections or acceptances. Deployment should be accompanied by user education, robust backup and recovery options, and additional controls such as monitoring, conditional access, and incident response planning.

See also: multifactor authentication, two-factor authentication, biometrics, FIDO.