Simply generate an ssh-key and add it's public key to your GitHub account to be able to authorize your computer to remotely login and connect to it.
This has been tested on Ubuntu OS, but should fairly work the same on other Linux Distributions.
Notes: If you are using an existing ssh key, proceed to Step 2.
Open a terminal and type
ssh-keygen -t rsa -b 4096 -C "firstname.lastname@example.org".
$ ssh-keygen -t rsa -b 4096 -C "email@example.com"
You will be asked where to save the file, just hit
Enter a hard-to-guess passphrase. Do not forget your passphrase, you will be needing this in your future ssh connections.
SSH key has been created.
$ eval "$(ssh-agent -s)"
$ ssh-add ~/.ssh/id_rsa
Open the file id_rsa.pub. Just leave it open in the meantime, you will copy all of it's contents later.
$ gedit ~/.ssh/id_rsa.pub
Login on github and click the View profile and more link located at upper right corner of the page.
Click SSH Keys.
Click Add SSH Key.
On the Title field, type something that would remind you in the future that you are the one who added such SSH key. Next, is the time to copy all that's inside id_rsa.pub to the field Key. Lastly, click Add key.
It will appear on the list of keys. You can now close id_rsa.pub file, and log out your github account.
ssh -T firstname.lastname@example.org on the terminal.
$ ssh -T email@example.com
Your ssh connection was successful when you see a message similar below.