Passwordless Logins with SSH
SSH allows you to login remote hosts without entering your password every time, using Public key authentication.
First you need to generate key,
$ ssh-keygen -t rsa
Save the key in the default file (~/.ssh/id_rsa) and do not use a passphrase. This will create a file ~/.ssh/id_rsa.pub.
You need to copy your public key to all machines that you need to login with this scheme.
$ scp .ssh/id_rsa.pub user@host:.
Finally append your public key to the available keys,
$ cat id_rsa.pub >> .ssh/authorized_keys