An information processing device updates its own secret key according to an update request including request order information, the information processing device being provided with: a storage unit that stores, in a nonvolatile manner, a master secret key, a secret key, and order comparison information that enables comparison of the request order of the update request; and an update unit that, in a case where the update request has been made, compares the request order information and the order comparison information, and in a case where it has been determined that the order of the update request is authorized, updates the order comparison information to information corresponding to the request order information before update processing of the secret key is performed by using the master secret key.