FIDO stands for Fast IDentity Online. It is a set of open, licence-free standards and protocols developed by the FIDO Alliance for secure and more user-friendly authentication on the Internet. There are several implementations of FIDO, including FIDO U2F (Universal Second Factor) and FIDO2, which are widely used in modern web browsers and platforms. Using these protocols, passwordless two-factor authentication based on public-key cryptography is possible.

The main goal of the Security key (Security Key / FIDO-Token) is to address the known weaknesses of the standard user login with username and password as well as simple two-factor authentications (email, AuthApp, SMS).

FIDO2 allows either two-factor authentication, in which the usual username-password login is supplemented by encryption with FIDO2 keys and an additional FIDO2 token (hardware), or completely password-free authentication, which works without entering a password. Even if the login data should be compromised, the FIDO2 login only succeeds with the respective hardware token or the private key, which is also bound to a dedicated hardware. Biometric data, if such a feature is used, never leaves the user device.

Security key (Security Key / FIDO-Token) are procured by the end users themselves in the electronics trade. Depending on the manufacturer and the type (connection type, PIN, biometric), these cost between 20 and 120 Swiss Franc.