According to Fedora wiki they're used to create OTPs (one time passwords), but still... I don't like the idea of a physical token that can be stolen and used without verifying the user (meaning that you still need user/password or any other auth mechanisms to complement the Yubikey).
Yeah you will still need username/pass for google I'm sure. Although they mentioned something about a ring? NFC maybe?
If you run your own server, though, you can set up challenge-response on the Yubikey which might make things easier by allowing maybe a PIN instead of a password.
Hopefully one day soon we will be able to authenticate with behavior; maybe a combination of gate/speech cadence/facial structure. Or maybe like a Rorschach test instead of username/password field :)
According to Fedora wiki they're used to create OTPs (one time passwords), but still... I don't like the idea of a physical token that can be stolen and used without verifying the user (meaning that you still need user/password or any other auth mechanisms to complement the Yubikey).