Use the stuff from that Mozilla wiki page and OpenSSH will be secure enough already. Unless more vulnerabilities are found that apply to such a configuration, o

Use the stuff from that Mozilla wiki page and OpenSSH will be secure enough already. Unless more vulnerabilities are found that apply to such a configuration, or keys are compromised, port knocking in this case isn't going to stop anyone that OpenSSH wouldn't already stop on its own. It's effectively just a pointless layer of security that only adds more hassle to connect. I'm not saying that port knocking doesn't have uses, just that it doesn't in this case. Unless you're trying to hide the service I guess, but I don't see why that would be necessary.