$ ssh-keygen -t rsa -b 4096
This will create two files in your (hidden) ~/.ssh directory called id_rsa and id_rsa.pub. id_rsa is your private key and id_rsa.pub is your public key.
Now set permissions on your private key:
$ chmod 700 ~/.ssh $ chmod 600 ~/.ssh/id_rsa
Copy the public key (id_rsa.pub) to the server and install it to the authorized_keys list:
$ cat id_rsa.pub >> ~/.ssh/authorized_keys
Note: once you've imported the public key, you can delete it from the server.
and finally set file permissions on the server:
$ chmod 700 ~/.ssh $ chmod 600 ~/.ssh/authorized_keys
A good practice will also be to disable password authentication, forcing use of keys.@ /etc/ssh/sshd_config