A bus system includes a functional unit to which a unit identifier is assigned, a memory module for storage of data that has a storage region, and a bus. The functional unit is connected to the memory module via the bus. The storage region is configured such that one or more multiple global authorized identifiers are assigned thereto, so that the functional unit only has reading or writing access to the storage region if the unit identifier assigned to the functional unit corresponds to one of the global authorized identifiers assigned to the storage region.