Make Tech Easier published a quick tutorial about how to generate a public/private SSH key in Linux.
How to Generate A Public/Private SSH Key in Linux
If you are using SSH frequently to connect to a remote host, one way to secure your SSH server is to use a public/private SSH key so that no password is transmitted over the network. It can prevent against brute force attack too. In Linux, creating a public/private SSH key is easy.
How to Generate A Public/Private SSH Key in Linux