If you create an ssh public/private key pair, you will be able to login to any CoC machine you have access to without entering your password. The use of clear text remote access utilities (e.g. telnet, rlogin, rsh, rcp, .rhosts) is prohibited. The setup of ssh public/private key is relatively simple, follow these steps:

$ mkdir ~/.ssh
$ chmod og-rwx ~/.ssh
$ ssh-keygen -b 2048 -t rsa -f ~/.ssh/id_rsa
$ cp ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys