I posted a message about disturbingly plentiful root logon dictionary
attacks that I saw in my logs.

The solution that works and I like the most is:

in /etc/ssh/sshd_config

PermitRootLogin without-password

That means that root logons are allowed ONLY with keys. No passworded
logins are allowed as root -- one MUST have a key.

I think that it is just what I need!

i