Secure high level communication protocol for CAN bus

The Controller Area Network (CAN bus) is a bus based on differential signalling originally developed for automotiv industry. The bus was later standardized under ISO 11898 and the standard describes data link layer as well as physica signalling. CAN bus allows precise settings of bus timing and sampling points, which makes it usable for varying range and baudrates. It also has a number of properties such as: message acknowledgement, collision avoidance, messag filtering and automatic retransmit of faulty messages. These properties make it suitable for many applications Furthermore, the bus is also well supported on microcontrollers and can even be found on larger SoCs. This makes th CAN bus ideal for microcontroller networks in buildings Unfortunately, the CAN protocol itself has no support for node authentication and message encryption so thes requirements has to be solved on higher layer. We present a high-level protocol for CAN bus that supports authenticatio and encryption and therefore allows usage of CAN bus in security dependent systems such as an access managemen system or in industrial automation