Multi-factor Authentication

security

Definition

Multi-Factor Authentication

Multi-factor authentication employs multiple authentication methods from different classes — knowledge, ownership, and inherence — together for user authentication.

The goal is to overcome the limits of one authentication method via the others.

Same-Class

Same-Class Combination Is Not MFA

Password (knowledge) + PIN (knowledge) is not multi-factor authentication. The factors must belong to different classes.

Examples

Two-Factor Combinations

• Password (knowledge) + OTP generated with a hardware token (ownership).
• Face recognition (inherence) + authenticator app installed on the phone (ownership).

Three-Factor Combination

• Password (knowledge) + OTP from a TAN list (ownership) + fingerprint (inherence).