A Proposal for Data Authentication, Data Integrity and Replay Attack Rejection for the LIN Bus

Today’s most relevant in-vehicle communication buses (CAN, LIN, FlexRay) offer no standard cybersecurity features, being highly vulnerable to local and remote cyberattacks, targeting the onboard computer and spreading to the vehicle’s electronic control units through the aforementioned buses. Cybersecurity proposals for CAN and FlexRay have been introduced in the past, from various authors; no such proposal for the LIN (Local Interconnect Network) bus has been presented yet. This paper presents a computationally-feasible, real-time and hash-based message authentication code (HMAC) scheme, for the LIN bus. This proposal provides message integrity check and authentication, and uses a node’s internal timestamp in order to reject replay attacks.