To set up SSH login without passwords using keys:
1. Generate key using ssh-keygen utility. Keys will be saved in this example in ~/.ssh/ folder. File ~/.ssh/id_rsa is your private key. File ~/.ssh/id_rsa.pub is your public key.
2. Add public key to ~/.ssh/authorized_keys on server where you want to login without password using command:
# ssh-copy-id -i ~/.ssh/id_rsa.pub email@example.com
3. Now you can login as user to example host shkodenko.com without password using your public key using command:
# ssh firstname.lastname@example.org