This assumes that you have at least two machines, a host machine and a remote machine (the one that you want to log onto). Please note you do need to have a user account on both machines with the same name.

On the host machine open terminal at the prompt (you don't type the % below) type the following :

% ssh-keygen -t rsa

This will generate a pair of public keys, one stays on the host machine and the other is moved to the authorized keys directory on the remote machine.

So using bbedit, navigate to your user home directory :

/Users/your_users_name

and from there to the :

.ssh directory

- this is a hidden directory so you may need to change your bbedit to "Show" all files ( at the top of the window, below the menu bar)...

.. and open the file:

id_rsa.pub

Or using terminal :

% cd /Users/your_users_name/.ssh

% bbedit id_rsa.pub

copy the the complete line of text you find here and paste

into the " authorized keys" file found in the same place on the remote machine. If this file does not exist, just create a file with this name.