An arrangement on monitoring of authentication, in particular for motor vehicles, includes a first communication apparatus and at least a second communication apparatus, between which a wireless communication channel can be set up. The communication apparatus items have means for authentication and encryption, with which the exchangeable data may be encrypted via the communication channel. The items of communication apparatus have storage means in which one of the digital keys usable for authentication and encryption can be stored, and in that in the storage device there is either in addition to the digital key and/or in the individual key at least one piece of information regarding at least one past communication between the first communication apparatus and the second apparatus that can be stored in memory.