U2F support in OpenSSH
https://marc.info/?l=openssh-unix-dev&m=157259802529972&w=2 [marc.info]
2019-11-03 20:26
As of this morning, OpenSSH now has experimental U2F/FIDO support, with U2F being added as a new key type “sk-ecdsa-sha2-nistp256@openssh.com” or “ecdsa-sk” for short (the “sk” stands for “security key“).
Also: https://marc.info/?l=openbsd-tech&m=157376801917387&w=2