YubiKey does TOTP (time based OTP) by storing the shared secret on the key and having the connected system pass in the system time. It's more secure as the shar

YubiKey does TOTP (time based OTP) by storing the shared secret on the key and having the connected system pass in the system time. It's more secure as the shared secret is write only, compared with having google authenticator on the phone storing the shared secret in your phone's storage. See http://www.yubico.com/wp-content/uploads/2014/02/Yubico-TOTP-Setup.pdf http://www.yubico.com/wp-content/uploads/2014/02/Yubico-TOTP...