Having SSH key access to your server adds extra door/s of protection, plus instead of needing a password potential hackers now need a key and a password.
Generate you keys using putty key generator. Save the public and private key in safe place with a name you can recognize.
Category: Linex
Disable SSH password login on Ubuntu
How to disable normal username/password login authentication to your Ubuntu server, only allowing SSH key authentication. This gives you the advantages of SSH’s whilst securing your server that little bit more.
Disable SSH key authentication
SSH server in most systems is by default configured to allow public-key authentication. The method will enable you to use your public and private key pair to passwordlessly log in to an SSH server instead of the typical username and password method.