# Security Keys (U2F) **Authelia** offers authentication using Security Keys like [Yubikey](Yubikey) which are one of the most secure way to authenticate and get authorized. It is already available for Google, Facebook, Github accounts and more. The protocol requires your security key to enrolled before authenticating. To do so, select the *Security Key* method at the second factor stage and click on the link *Not registered yet?*. This will send a link to your user email address. This e-mail will likely be sent to https://mail.example.com:8080/ if you're testing Authelia and you've not configured anything. Confirm your identity by clicking on **Register** and you'll be asked to touch the token of your security key to enroll.