Use ssh-keygen command as follows:
$ ssh-keygen -t dsa
Enter file in which to save the key (/home/usernane/.ssh/id_dsa): Press [Enter] key Enter passphrase (empty for no passphrase): myPassword Enter same passphrase again: myPassword Your identification has been saved in /home/username/.ssh/id_dsa. Your public key has been saved in /home/username/.ssh/id_dsa.pub. The key fingerprint is: 04:be:15:ca:1d:0a:1e:e2:a7:e5:de:98:4f:b1:a6:01 username@username-desktop
Caution: a) Please enter a passphrase different from your account password and confirm the same.
b) The public key is written to /home/you/.ssh/id_dsa.pub.
c) The private key is written to /home/you/.ssh/id_dsa.
d) It is important you never-ever give out your private key.