How to setup your linux server with SSH Keys Print

SSH keys provide an easy and secure way of logging into your server and we recommend it for all installations.

Ok let's start, first step is to create a key pair on the client machine

ssh-keygen

You may optionally pass in the -b 4096  flag to create a larger 4096-bit key. By default a  2048-bit RSA key pair will be created.
Output of ssh-keygen:

Generating public/private rsa key pair.
Enter file in which to save the key (/your_home/.ssh/id_rsa):

Press enter to save the key pair into the .ssh/ subdirectory in your home directory.
Output is:

Enter passphrase (empty for no passphrase):

Optionally you may enter a secure passphrase. In this case we just hit ENTER for no pass.
Output is:

Your identification has been saved in /your_home/.ssh/id_rsa.
Your public key has been saved in /your_home/.ssh/id_rsa.pub.
The key fingerprint is:
a9:49:2e:2a:5e:33:3e:a9:de:4e:77:11:58:b6:90:26 username@remote_host
The key's randomart image is:
+--[ RSA 2048]----+
|     ..o         |
|   E o= .        |
|    o. o         |
|        ..       |
|      ..S        |
|     o o.        |
|   =o.+.         |
|. =++..          |
|o=++.            |
+-----------------+

Your  keys are now ready to use. Next step is to place the public key on your server so that you can use SSH-key-based authentication .
Quickest way to copy your public key to the remote host is to use a utility called ssh-copy-id


ssh-copy-id username@remote_host

Now you should be able to log into the remote host without the remote account’s password :

ssh username@remote_host

Key-based authentication works,  now secure your server by disabling password authentication.