This section describes how to set up OpenSSH on the client side.
The configuration files provided with most distributions establish a mostly secure system that might or might not meet your needs. One OpenSSH parameter you might want to change is ForwardX11Trusted, which is typically set or defaults to yes in the /etc/ssh/ssh_config configuration file (page 701). To increase security, and in some cases reduce usability, set ForwardX11Trusted to no. See page 706 for more information on X11 forwarding.
Two files list the hosts the local system has connected to and positively identified: ~/.ssh/known_hosts (user) and /etc/ssh/ssh_known_hosts (global). ...