What is multi-factor authentication?

Multi-factor authentication (MFA) is an authentication method that significantly enhances security by requiring two or more verification factors to gain access to a system or account. This approach reduces the likelihood of unauthorized access, as it necessitates not just something the user knows (like a password), but also something they have (such as a smartphone for receiving a one-time code) or something they are (like a fingerprint or facial recognition).

By combining different types of factors, such as knowledge-based (passwords), possession-based (smartphones or security tokens), and inherence-based (biometric data), MFA creates layers of security. Even if one factor is compromised, unauthorized individuals would still need the additional factors to gain access, hence improving overall security posture.

The other methods mentioned do not fulfill the criteria for multi-factor authentication. Relying only on a password or a single verification code lacks the required multiple layers of security. Using biometrics exclusively also does not incorporate other verification measures that would constitute a multi-factor approach.