I use the YubiKey for SSH auth on several servers but didn't go the GPG route. I opted for the challenge SSH mode using PAM. Using username "gunni". Using

I use the YubiKey for SSH auth on several servers but didn't go the GPG route. I opted for the challenge SSH mode using PAM. Using username "gunni". Using keyboard-interactive authentication. YubiKey for `gunni': Using keyboard-interactive authentication. Password: Last login: Tue Jan 14 14:07:02 2018 from X [gunni@box ~]# Works like a charm but I might look into the PGP variation if one of you can hard sell it to me.