Method for transmitting messages between control units of a motor vehicle, and switch apparatus, and motor vehicle

A switch apparatus for a motor vehicle having control units and a data network with network branches, comprising:

• connection ports provided to connect the network branches of the data network, at least some of the connection ports set up for operation as input ports receiving messages transmitted with a time delay by at least two of the control units performing time synchronization, such that the messages are interlaced and arrive at the switch apparatus alternately and without collisions, and at least some of the connection ports set up for operation as output ports;
• and
• a processor configured to
• control the messages received at the input ports with an address indication of a destination address and a priority indication of a priority level from among a plurality of priority levels indicated by cryptographically encrypted priority data, each input port of the switch apparatus receiving at most a predetermined maximum data volume overall, for at least one priority level during each predetermined unit of time,
• assign each of the messages received at the input ports to one of the output ports, based on the destination address, that outputs each of the messages assigned thereto, and
• at least one of decrypt the priority data based on a cryptographic key, and the switch apparatus having a cryptographically secure internal configuration.

A motor vehicle, comprising:

• a data network with network branches;
• control units outputting messages, containing an address indication of a destination address and a priority indication of a priority level from among a plurality of priority levels indicated by cryptographically encrypted priority data, at least two of the control units performing time synchronization, such that the messages are output interlaced with a time delay that prevents collisions;
• and
• at least one switch apparatus, via which the control units are coupled and the messages are interchanged, the at least one switch apparatus respectively including
• connection ports connected to the network branches of the data network, at least some of the connection ports set up for operation as input ports receiving the messages transmitted from the control units, each input port receiving at most a predetermined maximum data volume overall for at least one priority level during each predetermined unit of time, and at least some of the connection ports set up for operation as output ports outputting the messages assigned thereto, and
• a processor configured to
• control the messages received at the input ports,
• assign each of the messages received at the input ports to one of the output ports based on the destination address, and
• at least one of decrypt the priority data based on a cryptographic key, and the switch apparatus having a cryptographically secure internal configuration.