I've found using private key login with ssh is the best way to leave backdoors. Very few inexperienced administrators will look for the keys. Some even leave yo

I've found using private key login with ssh is the best way to leave backdoors. Very few inexperienced administrators will look for the keys. Some even leave your user account on the server after you are gone. I was able to get into some sites I formerly had access to because my private key was never revoked. It was a bit of irony to use that same "unauthorized" access to remove my own key from the authorized_keys file.