# Since this is a critical file, back it up first.
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.2011-02-12.v0.0.tinpham_about_to_disable_password_auth.bck
# Load the file in your favourite editor.
sudo vi /etc/ssh/sshd_config
Adjust We can modify sshd_config quickly using sed,
sudo sed -i 's/#PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config
Changes the following,
# Change to no to disable tunnelled clear text passwords
Remove the comment Uncomment and change yes to no. It should look like this,