PUBLICKEY="YOUR_PUBLIC_KEY_HERE"
echo "ssh-rsa $PUBLICKEY" >> ~/.ssh/authorized_keys
cat ~/.ssh/authorized_keys
sed -i 's/UsePAM yes/UsePAM no/g' /etc/ssh/sshd_config
sed -i 's/ChallengeResponseAuthentication yes/ChallengeResponseAuthentication no/g' /etc/ssh/sshd_config
sed -i 's/PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config
service sshd restart