What is the term for a person under a duty to safeguard a proprietary secret?

The correct answer is the term "fiduciary," which refers to an individual or entity that has the legal and ethical obligation to act in the best interest of another party, particularly in situations involving trust and confidential information. A fiduciary relationship is characterized by the duty to protect the interests and secrets of the party to whom the obligation is owed, including proprietary secrets. This applies in various contexts, such as financial advisors, lawyers, and business partners, where the safeguarding of sensitive information is paramount.

In the context of proprietary secrets, a fiduciary relationship ensures that the individual entrusted with the secrets is legally bound to maintain confidentiality and not exploit that information for personal gain or to the detriment of the owner. This duty is critical for maintaining trust and integrity in business relationships and transactions.