I’m sure you have seen something like this when you have connected to a ssh host.
The authenticity of host 'host (18.104.22.168)' can't be established.
RSA key fingerprint is 44:99:ff:33:66:88:cc:66:aa:22:00:00:ee:11:99:33.
Are you sure you want to continue connecting (yes/no)?
Great. Now what? What to do with that cryptic garbage up top? Log into the box or call the admin over the phone and verify the key.
$ ssh-keygen -l -f /etc/ssh/ssh_host_key.pub