two-factor authentication
Two-factor authentication (noun) means a way of checking that someone is who they claim to be by asking for two different kinds of proof, typically a password plus a second item such as a code from a phone app, a text message or a small physical key. Example: “Turning on two-factor authentication means a stolen password on its own is not enough to get into the account.”
How to use two-factor authentication
Learner’s notesIn plain EnglishLogging in needs two things instead of one, usually your password and a code.
Neutral and standard. Almost always shortened to 2FA in running technical text and in interface labels; the full form is used on first mention and in formal writing.
The hyphen goes in the modifier: 'two-factor authentication', but 'authentication with two factors'.
Fill the gap
Can you complete this real example?
Turning on _____ means a stolen password on its own is not enough to get into the account.