On your client machine, execute:
#ssh-keygen -t dsa -P ” -f ~/.ssh/id_dsa
This will create a file called id_dsa.pub in ~/.ssh/
Copy that file to your destination host under ~/.ssh/
#cat ~/.ssh/id_dsa.pub ~/.ssh/authorized_keys
This will append the content of id_dsa.pub to authorized_keys; you can now access your host without the password prompt.
You can disable password authentication completely by adding the following setting to your /etc/ssh/sshd_config file:
+Disable password authentication forcing use of keys