Ubuntu/Debian:
sudo apt-get install -y openssh-server
CentOS/RHEL:
sudo yum install -y openssh-server
Create Keys:
Note: This does NOT matter what server you make them on, and the end of the public key, which has your username & computer name, is JUST A COMMENT. You can delete it.
ssh-keygen -t rsa
Copy your keys to a safe location!
id_rsa = Private Key id_rsa.pub = Public Key (Store in ~/.ssh/authorized_keys)
Now just follow my guide on setting up your server w/ your RSA Keys. You should keep these keys in a safe place.