No, and what you want is DRM and not security. The base of any measure of security is that only you have “root” level access to the server as the root user will be able in the end to overcome any DRM measure you try to implement.
If a contract will not stop him from violating your rights (assuming you have them at all), nothing will stop him.
If you want to restrict your user in such a away as you imply, you should not give him root/ftp access to the server.