[K12OSN] How do I stop attempted logins

[Dr. Daniel Loomis]

I have remote access setup for our server so I can transfer files, check
logs, and do maintenance from home.  I have it setup using a
public/private key-pair, with password login disabled.  Root logins are
also disabled.  I have it setup to only allow one non-privileged user in
the /etc/ssh/sshd_config file.

No login prompt is ever presented to the outside world on port 22. 
However, I still get hundreds of attempts each day from automated probes
usually at intervals of 1-2 seconds.  None have been able to breakin
since I do not accept password logins.  Here is what is presented to
anyone trying to login on port 22:

  FIRST PRESBYTERIAN CHURCH LIBRARY
  Password Login = Disabled
  Permission denied (publickey).


I have considered changing to a non-standard port, but I suspect that a
simple portscan would quickly discover it and the attempts would
continue.

My /var/log/secure files are filling up fast with these repeated breakin
attempts.  I have done a whois on several of the addresses.  Most seem
to be coming from Taiwan and other places in Asia.

Is there some way to stop this infernal nuisance?  

RevCurmudgeon