Limiting access to only those who have my certificate

I there a way to prevent to sshd from responding to anyone without a certificate created and signed on the server? Basically I am trying to be as secure as possible with my ports and I was thinking that if I could basically construct a certificate that I stored on a floppy, I could eliminate the possibility of someone guessing the password. Then as long as I never let anyone have a copy of the certificate file, my sshd would remain impenetrable. Is this possible to do? Will it do what i want? Am I crazy to be so concerned?

Thanks for any help in advance.

Jason Corekin Received on Fri Dec 13 13:09:58 2002