Multi Factor Password Authentication
From James's Wiki
install with:
sudo apt install libpam-google-authenticator
configure with: (scan the barcode into your phone app while you are doing this)
google-authenticator
edit file:
sudo nano /etc/pam.d/sshd
add the following line to the bottom:
auth required pam_google_authenticator.so
edit the ssh server configuration
sudo nano /etc/ssh/sshd_config
change the line and make it look like this
ChallengeResponseAuthentication yes
restart ssh