People already mentioned the NFC, but you can also use the key on another secure...

bduerst on July 23, 2018 | parent | context | favorite | on: Google: Security Keys Neutralized Employee Phishin...

People already mentioned the NFC, but you can also use the key on another secured device (w/ USB) to generate an OTP for the phone login. This still requires using the key to get the temporary OTP.