Demo authenticator which sends a magic link to the user with which the user can authenticate without needing to provide a password.
This moves the security from the users knowledge to its mailbox!
To provide a bit more security than just sending a link via e-mail, the authentication has to be finished where it was started. So this has to happen in the same browser. It's not possible to start the authentication on your phone and click the link in the mail on your desktop (or vice versa), this won't work. (Or, if you want this get to work, you will have to implement another way, more complex!)