This howto should help you with setting up an RSA public and private key setup from a Mac to an Ubuntu box. Of course, this should be possible with other OS’s but I have not tested it. Please post if it was useful!
For the past week I have been trying to set up an RSA SSH certificate for accessing my Ubuntu servers from PuTTY and Mac’s SSH through a terminal. However I have been faced with some serious problems, thankfully the guys over at ubuntuforums.org could help me out. So here is a quick howto I wrote so that people don’t have the same kind of trouble that I did.