RSA key how to and tips

Disable root password, SFTP access, WordPress update with a RSA key.

Root password :

Disable the password access with root login for SSH.

Setup :

Setup a RSA key.

SFTP :

SFTP access and RSA key with WordPress.
Use FileZilla and RSA key.
ProFTPD SFTP virtual users redirected to www.

WordPress :

WordPress and RSA key with FTP access.

Info :

One SSH server keys and multiple devices.