Method for monitoring communication on a communication bus, electronic device for connection to a communication bus, and vehicle

Abstract

The invention relates to a monitoring method for a communication bus (104). This method detects unauthorized bus access. The method involves providing a monitoring module (1517) at a station connected to the communication bus (104). In this method, messages are marked by an identifier, and for each station (140-163), it is defined which messages with which identifier it is permitted to send. A uniqueness rule prohibits another station (152, 153) from sending a payload message with an identifier already reserved for that station (151). This rule is exploited during monitoring by checking whether a payload message with an identifier reserved for the station (151) is being sent on the communication bus (104) by another station (152, 153).If so, unauthorized bus access has been detected. One or more of the following countermeasures are then initiated: Disabling the injected message by overwriting the message with the dominant level, by overwriting the message with a specific bit pattern, by selectively modifying a specific part of the message, such as the CRC field, or by setting an information entry in an additional field of the transmitted messages; warning another electronic station (140-163) by sending implausible data content in one or more subsequent messages, or by sending a warning in one or more dedicated warning messages.