Glossary A–ZLetter T
Two-factor authentication
With two-factor authentication, a person proves their identity with two independent pieces of evidence, usually something they know (a password) and something they have (a smartphone or security key).
A stolen password alone is then no longer enough.
Common options are one-time codes from an authenticator app, which usually change every 30 seconds, as well as security keys and passkeys; codes sent by text message are considered a weaker option. In the management software of a screen network, the second factor is particularly worthwhile for administrators and anyone who can push content to many screens, because a hijacked account can show unauthorised content on every screen in the network.
The case of a lost smartphone matters: recovery codes must be stored securely, and an administrator needs an orderly way to reset the second factor. Technical credentials such as interface keys have no second factor and need other safeguards, such as tightly limited permissions. When signing in with a company account (single sign-on), the central identity service usually handles the second factor.