I believe they're describing U2F, and share your perception that at some point in the past these were just keyboards. [1] describes the flow at a high level, a

I believe they're describing U2F, and share your perception that at some point in the past these were just keyboards. [1] describes the flow at a high level, and [2] goes into more details [1]: https://www.yubico.com/about/background/fido/ https://www.yubico.com/about/background/fido/ [2]: https://developers.yubico.com/U2F/Protocol_details/Overview.html https://developers.yubico.com/U2F/Protocol_details/Overview....