Suggestion: Install Ubuntu Server Guide

$ sudo apt-get install ubuntu-serverguide

Access this from System/Help and Support/Advanced Topics/Ubuntu Server Guide



Encryption

Public/Private Key encryption


OpenSSH

$ sudo apt-get install openssh-server openssh-client


$ ssh lastname@10.50.46.38

linux@linux-desktop:~$ sudo vi /etc/hosts

add 

10.50.46.38	darna


linux-desktop:~$ ssh darna      # assumes same username on
                                  darna as on linux-desktop
linux-desktop:~$ ssh -l pareja darna
				# use pareja as login name
				  on darna
linux-desktop:~$ ssh pareja@darna   # use pareja as login name
                                   on darna

defaults to running a shell on the remote machine

linux-desktop:~$ ssh darna command # will connect to darna,
                                # then execute command


~~~~~~~~~~~~
Generate an ssh key

linux-desktop:~$ ssh-keygen     # create a public/private 					keypair

linux-desktop:~$ ssh-copy-id darna # copy public ID        to                           remote host

------
openssh-server config

/etc/ssh/sshd_config   <- config file for server
			man sshd_config

/etc/ssh/ssh_config    <- system config for ssh clients
  ~/.ssh/config        <- user config for ssh client
                        man ssh_config