Authentication requiring exactly two verification factors—a specific form of MFA.
Two-Factor Authentication (2FA) is a subset of MFA requiring exactly two verification factors. The terms 2FA and MFA are often used interchangeably, though MFA can include more than two factors. Common 2FA combinations include password plus SMS code, password plus authenticator app, or password plus hardware token. While any second factor improves security, authenticator apps and hardware tokens are more secure than SMS codes.
Why It Matters
The DSC Perspective:
2FA is better than passwords alone, but not all 2FA is equal. SMS-based 2FA is vulnerable to SIM swapping; authenticator apps are more secure; hardware keys are strongest. Choose appropriate strength for the risk.