How to create a private and public key pair with PUTTYGEN
This guide describes how to generate and use a private/public key pair to log in to a remote system with SSH using PuTTY. Using key-based SSH logins, you can disable the normal username/password login procedure which means that only people with a valid private/public key pair can log in. That way, there is no way for brute-force attacks to be successful, so your system is more secure.