Glossary
Two-factor authentication
Two-factor authentication: Two-factor authentication (2FA) is a second check at login, usually a code from an app or a text, so that a stolen password alone is not enough to get in.
Updated February 1, 2027
An example
After typing your password, you approve the login in an authenticator app on your phone.
Why it matters to you
Turn it on for email, bank and phone carrier accounts. Prefer an authenticator app or passkey over text codes, which can be intercepted by a SIM swap.
Where to go next
See also
- Passkey
A passkey is a login method that replaces your password with a cryptographic key stored on your phone or computer and unlocked with your face, fingerprint or device PIN; it cannot be phished because it only works on the real site.
- SIM swap
A SIM swap is an attack in which a scammer convinces your phone carrier to move your number to their phone, so that they receive your calls and text-message login codes.
- Authenticator app
An authenticator app generates the six-digit login codes used for two-factor authentication on your phone, without needing a text message.