The below reference to Google documentation is no longer true.
Google recommends removing SSH keys from GCE instance to secure SSH. That does not make any sense to me. The keys are there for a security, right? When I remove the keys, SSHD stops working. I probably miss their point. Can someone explain what do the mean by this:
Remove ssh host keys
Don't use ssh host keys with your instance. Remove them as follows:
rm /etc/ssh/ssh_host_key rm /etc/ssh/ssh_host_rsa_key* rm /etc/ssh/ssh_host_dsa_key* rm /etc/ssh/ssh_host_ecdsa_key*
StrictHostKeyChecking
and later recommends disabling it. I suspect it isn't a very carefully edited document. My advice is to trust your own judgment, and use host keys unless there's a good reason not to.