I agree that moving the sshd port is no guarantee of anything, but I
would still recommend it. That much noise is very bad (dozens/hundreds
of attempts 24/7) and makes it harder to see a real threat. I sleep
easier anyway :-)
I use both keys and strong passwords.
Another useful component is an intrusion detection kit - I use aide.
Again, no guarantee, but a useful part of the armoury.
--
Alastair Sherringham