A Dynamic Key Generation Scheme Based on CAN Bus

With the widespread use of CAN bus, more and more security issues are exposed. Traditional fixed preset keys are easier to be cracked after long-term use, the risk of key leakage can be caused by physical intrusion; Assigning different keys to different ECUs also leads to extremely high cost of key management . In order to ensure the safety of CAN bus transmission and reduce the complexity of system, this paper proposes a dynamic key generation algorithm. All ECUs obtain their own transient values and current timestamps when the car starts, complete the generation of the master key MK by the ECC algorithm, and generate the current session key in combination with the timestamp to encrypt the message. When the car is turned off, all keys are deleted and regenerated next time when the car starts. It is verified by analysis that the generation scheme can effectively reduce the complexity of key management and improve key security.