Abstract: A secure hardware-based module or Security Electronic Control Unit (SECU) for a Controller Area Network (CAN) prevents an attacker from sending malicious messages through the CAN bus to take over control of a vehicle. The SECU shares a unique key and counter with each ECU on the CAN bus. When a legitimate ECU sends a message, it first compresses the message and then generates a MAC of the counter and a secret key. The counter is increased by one for each transmitted message. The ECU then fits the compressed message and the MAC into one CAN frame and sends it onto the CAN bus. The SECU performs the message verification on behalf of the intended receiver(s) of the message. If the verification passes, the receiver(s) simply decompress the message and use it as a normal CAN message. If the verification fails, the SECU will corrupt the CAN frame before it is fully received by the intended receiver(s). The corrupted CAN frame will be ignored by the intended receiver(s) as if it was never received.

Abstract: A secure hardware-based module or Security Electronic Control Unit (SECU) for a Controller Area Network (CAN) prevents an attacker from sending malicious messages through the CAN bus to take over control of a vehicle. The SECU shares a unique key and counter with each ECU on the CAN bus. When a legitimate ECU sends a message, it first compresses the message and then generates a MAC of the counter and a secret key. The counter is increased by one for each transmitted message. The ECU then fits the compressed message and the MAC into one CAN frame and sends it onto the CAN bus. The SECU performs the message verification on behalf of the intended receiver(s) of the message. If the verification passes, the receiver(s) simply decompress the message and use it as a normal CAN message. If the verification fails, the SECU will corrupt the CAN frame before it is fully received by the intended receiver(s). The corrupted CAN frame will be ignored by the intended receiver(s) as if it was never received.