An apparatus for communicating, including a communicating unit that enables the apparatus to communicate with a communications counterparty via the communicating unit. The communicating unit includes a unit for providing an individual certificate that is a digital certificate being provided with information identifying the apparatus for communicating in order to receive an authentication by the communications counterparty when communicating, and a unit for communicating when having been authenticated with the individual certificate by the communications counterparty. The apparatus further includes at least one storage area for storing the individual certificate and a common certificate that is a digital certificate not being provided with apparatus identifying information, in a replacement component as a minimum unit enabled for replacement.