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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 797

Multi-Factor Authentication (MFA)

Reviewed byCybersecurity entrepreneur & security researcher

What is Multi-Factor Authentication (MFA)?

Multi-Factor Authentication (MFA)An authentication method that requires two or more independent factors — typically from different categories — before granting access.


Multi-Factor Authentication (MFA) increases assurance by combining factors from at least two of three categories: knowledge (password, PIN), possession (security key, smartphone, smart card) and inherence (fingerprint, face, voice). Even if one factor is stolen or phished, the others should still block the attacker. Phishing-resistant MFA based on FIDO2/WebAuthn or smart cards is strongly preferred over OTP via SMS or email, which are vulnerable to SIM swaps, server-side compromise and real-time phishing through reverse proxies. MFA is now a baseline control in standards such as NIST SP 800-63B, PCI DSS and most cyber-insurance requirements, and is one of the most effective controls against account takeover.

Examples

  1. 01

    Logging in with a password plus a tap on a FIDO2 security key.

  2. 02

    An admin console requiring a hardware token after a Windows Hello sign-in.

Frequently asked questions

What is Multi-Factor Authentication (MFA)?

An authentication method that requires two or more independent factors — typically from different categories — before granting access. It belongs to the Identity & Access category of cybersecurity.

What does Multi-Factor Authentication (MFA) mean?

An authentication method that requires two or more independent factors — typically from different categories — before granting access.

How do you defend against Multi-Factor Authentication (MFA)?

Defences for Multi-Factor Authentication (MFA) typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for Multi-Factor Authentication (MFA)?

Common alternative names include: MFA, Strong authentication.

Related terms

See also