Vehchain - an Experimental Study of a Blockchain-Based CAN Bus Security Solution

The Controller-Area-Network (CAN) Bus has become a vulnerable target because of its ability to manage real-time plaintext vehicle data. Vulnerabilities include Man-in-the-Middle (MitM), Sniffing, Spoofing, Replay, Denial-of-Service (DoS), and other attacks originating from embedded malware or external attacks from the connected Internet. The existing work for CAN Bus enhancement relies on a centralized authority, which causes a single point of security failure. This work discusses decentralized CAN Bus security through a blockchain-reminiscent method, improving the security against CAN Bus attacks. A lab test-bed is built using different Electronic Control Units (ECUs) for performance validation, including ECUs manufactured by Microchip Technology. Instead of simulation, which is employed in other approaches, security attacks are conducted on a Buick Encore vehicle. The results from this study exhibit that VehChain protects CAN Frame data from Sniffing, Spoofing, Replay, and Denial of Service (DoS) attacks by utilizing secure Hashed Message Authentication Codes (HMACs), message counters, and key synchronization.