Prepare your SSH daemon for key exchange authentication!

sshkeyprep.sh

# bootstrap
mkdir ~/.ssh
cd ~/.ssh

# create authorized_keys file
touch authorized_keys
# at this step, add authorized keys into the touch

# prepare file permissions
chmod 700 ~/.ssh/
chmod 600 ~/.ssh/authorized_keys

#disable password authentication
sudo sed -i "s/#PasswordAuthentication yes/PasswordAuthentication no/g" "/etc/ssh/sshd_config"
sudo sed -i "s/PasswordAuthentication yes/PasswordAuthentication no/g" "/etc/ssh/sshd_config"

#restart SSH server
sudo /etc/init.d/ssh restart