Setup public/private keys for ssh to make hosts trust each other for ssh without password.

ssh-keygen -b 2048 -t rsa -f ~/.ssh/id_rsa -C "you@example.com"

You can either put in a password for key encryption or just leave a blank password.

cat ~/.ssh/id_rsa.pub | ssh you@other-box 'cat - >> ~/.ssh/authorized_keys'

NOTE: If an older version of ssh is running on the remote host, you may have to use the ~/.ssh/authorized_keys2 file.)