I will setup ssh public key authentication on your server

I will setup on your Linux Server SSH Key Authentication and turn off Password login this will increase a security level for your server so only user with private file can login to your server via ssh/sftp.

Public key authentication is a way of logging into an SSH/SFTP account using a cryptographic key rather than a password.

For example, with SSH keys you can

• allow multiple developers to log in as the same system user without having to share a single password between them;
• revoke a single developer's access without revoking access by other developers; and
• make it easier for a single developer to log in to many accounts without needing to manage many different passwords.

How Public Key Authentication Works

Keys come in pairs of a public key and a private key. Each key pair is unique, and the two keys work together.

These two keys have a very special and beautiful mathematical property: if you have the private key, you can prove you have it without showing what it is. It's like proving you know a password without having to show someone the password.