Multifaktor

Multifaktor, short for multifactor authentication (MFA), is a security method that requires a user to present two or more independent credentials to verify their identity. The aim is to reduce the risk that a single compromised credential grants access, by combining factors from at least two different categories.

The common factor categories are: something you know (password or PIN), something you have (a hardware token, smartcard, or mobile authenticator), something you are (biometric data such as fingerprint or iris), and sometimes something you do (behavioral patterns). In practice, MFA deployments often mix two factors—for example, a password plus a one-time code from an authenticator app or a hardware security key, or a push notification approved on a mobile device.

How multifaktor works in reality varies by implementation. Two-factor authentication (2FA) is the simplest form, while MFA may require three or more factors for higher-sensitivity access. Popular approaches include time-based one-time passwords (TOTP), push-based approvals, hardware security keys using FIDO2/WebAuthn, and biometric verification. Some methods, such as SMS-based codes, are widely used but generally considered less secure due to interception or SIM-swapping risks.

Benefits and limitations: MFA increases security by making credential theft less sufficient for unauthorized access and mitigates phishing when phishing-resistant methods are used. Drawbacks include potential user friction, higher management and cost for organizations, device dependency, and privacy concerns, especially with biometric data. Password recovery, device availability, and accessibility considerations must be addressed.

Standards and trends: Security guidance from organizations such as NIST supports MFA for sensitive access. Standards and protocols include TOTP, HOTP, and WebAuthn/FIDO2 for phishing-resistant authentication. Adoption continues to grow across consumer and enterprise services.