A key generation device for a vehicle-internal communication system and a method for the vehicle-internal management of cryptographic keys comprises providing at least one secret for a vehicle-internal key generation device and generation of at least one new cryptographic key by the vehicle-internal key generation device on the basis of the at least one secret. The generation and providing of the at least one new cryptographic key takes place autonomously and is triggered by a key-exchange event, or a combination of key-exchange events. The key-exchange event may be one of a vehicle-internal change, an environmental change and a security key.