Multi-factor authentication (MFA) is a security procedure that uses two or more independent factors from different categories to confirm a user’s identity. It is considered one of the most important measures for securing user accounts. In addition to the usual standard login credentials such as username and password, at least one further form of identity verification is required.
Authentication factors can be divided into three basic categories:
- Knowledge – something the user knows (e.g., a password or PIN)
- Possession – something the user has (e.g., a smartphone or hardware token)
- Inherence – something the user is (e.g., biometric characteristics such as a fingerprint or facial recognition)
By combining multiple independent factors, MFA significantly increases the security of authentication processes and makes it more difficult for attackers to gain unauthorized access to accounts or sensitive data.
Difference Between MFA and Two-Factor Authentication
In many cases, MFA is equated with two-factor authentication (2FA). In fact, two-factor authentication is a specific form of multi-factor authentication that combines exactly two factors.
While MFA can generally include two or more factors, 2FA is limited to two proofs of identity. In practice, both terms are often used synonymously, as authentication methods usually employ exactly two factors.
A detailed explanation of how 2FA works, typical authentication methods, and practical application scenarios can be found in the glossary entry on two-factor authentication (2FA).
