What technique can protect a secret from a fully trusted user?

Question

I am programming a system using C#. My program generates a small message (a hash digest for a file) that I want to store on the hard disk - but I don\'t want the user to be

Answer 1

No. It is not possible. If the person has physical/full access to the machine, there is no way you can protect the harddisk on it without encryption.

The only way I could see of doing it is storing this message on a remote server that the user does not have access to.