What is Two-Factor Authentication? - Explanation & Meaning
Learn what two-factor authentication (2FA) is, how multi-factor authentication works, and why 2FA with passkeys is the standard for account security in 2026.
Definition
Two-factor authentication (2FA) is a security method that requires users to provide two different verification factors to prove their identity. By requiring a second factor in addition to a password, account security is dramatically increased.
Technical explanation
Authentication factors fall into three categories: something you know (password, PIN), something you have (phone, security key), and something you are (biometrics). 2FA combines two of these categories. TOTP (Time-based One-Time Password) generates a unique code every 30 seconds via apps like Google Authenticator or Authy based on a shared secret and the current time. SMS-based 2FA is less secure due to SIM-swapping and interception risks. Hardware security keys (FIDO2/WebAuthn) offer the strongest protection through cryptographic authentication that is phishing-resistant. In 2026, passkeys are the breakthrough: based on FIDO2 standards, they replace passwords entirely with device-bound biometric or PIN authentication, synchronized via cloud platforms. Multi-factor authentication (MFA) extends 2FA to three or more factors for highly sensitive systems. Adaptive MFA dynamically adjusts required factors based on risk signals such as location, device, and behavioral patterns.
How MG Software applies this
MG Software implements two-factor authentication as standard in all applications we build. We integrate TOTP authentication, WebAuthn for hardware security keys, and passkey support. Our own development tools and systems are secured with MFA. For clients, we advise on the optimal 2FA strategy, recommending passkeys as the primary option for the best balance between security and user experience.
Practical examples
- An online banking environment that requires a TOTP code via an authenticator app in addition to a password, ensuring stolen passwords alone are insufficient for unauthorized access.
- A company distributing FIDO2 security keys to all employees for phishing-resistant access to business-critical systems and cloud applications.
- A consumer application implementing passkeys so users log in with their fingerprint or Face ID without ever having to type a password.
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