Using SSH keys is very handy for not always having to enter your password when logging into SSH. I'll show you how to set this up.

1. Generate the key by running:

       ssh-keygen -t rsa
   

   • Press enter to accepted the default location of ~/.ssh/id_rsa
   • Enter your passphrase. Make it as secure as possible.

 

2. On my server, I have SSH running under a different port from the default, so I modified ~/.ssh/config as follows, obviously with different values:

       Hosts example.com
       Port 22000
   

   • To fix the permissions, execute:

         chmod 600 ~/.ssh/config
     

3. Transfer ~/.ssh/id_rsa.pub to the remote server:

       scp ~/.ssh/id_rsa.pub 
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    :~
   

4. Then, SSH to the remote server:

       ssh 
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5. Add the public key to the list of authorized keys:

       cat ~/id_rsa.pub >> ~/.ssh/authorized_keys
   

6. Fix the permissions:

       chmod 600 ~/.ssh/authorized_keys
   

7. Delete id_rsa.pub:

       rm -f ~/id_rsa.pub
   

8. Now you can exit the remote server:

       exit
   

9. Now, run ssh-agent so you only have to enter the key once:

       ssh-agent -s > ~/.ssh-agent
   

10. Bring the environment variables from ~/.ssh-agent into the current shell:

        source ~/.ssh-agent
    

11. Add the key to ssh-agent:

        ssh-add
    

    When prompted, enter your passphrase, as you entered in step 1.

12. Now, you should be able to run:

        ssh 
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    Without being prompted for your password.

Ref: http://www.perpetualseeker.com/?p=489