Disable Root login over SSH

These instructions are based on Debian.

Open file as root or sudo

vim /etc/ssh/sshd_config

Add or Edit the Following Lines

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Change to no to disable tunnelled clear text passwords
PasswordAuthentication no

UsePAM no

Save your work.

Restart SSHD

 service sshd reload

Or on some systems

/etc/init.d/sshd reload