ssh keys and permissions

create ssh keys in your local machine (if you don't have any yet)
ssh-keygen -t rsa

This will create two keys id_rsa and id_rsa.pub

In the remote machine, create a .ssh directory in your home directory
set permission to 700 by, chmod 700 .ssh

create an authorized_keys file in the .ssh directory by
touch authorized_keys

copy the public key into this file by,
cat id_rsa.pub >> authorized_keys

set the permission of authorized_keys to 640
Now you can access the remote machine without passwords!