Root Logins with Key Required

I love the fact that I still have so much to learn. I was thinking that I should set things up so that root can ssh in to a computer but only if they have keys set up. One very quick google search and I had my answer.

[[email protected] ~]# grep PermitRoot /etc/ssh/sshd_config
PermitRootLogin without-password

I had just assumed the settings for PermitRootLogin were yes or no. It's great that the programmers also had thought of this other use. People are so much smarter than me.