A great concept is to trust no one! But it depends on your idea, as to what can be stolen and how to safeguard it. We are dealing with an extremely delicate situation right now, where we are selling the "concept", without giving away the technical details that would compromise the sensitive information. If your concept is that sensitive, I would get an attorney to provide you with a Non-Disclosure/Non-Compete Agreement for your consultant to sign, before sharing information with him/her. Contact us for further clarification, if you wish.