Unified data authenticated encryption for vehicular communication

Sensitive data are usually transferred within a vehicle using FlexRay protocol. To prevent the in-vehicle data from the manipulation and man-in-the-middle attacks through On Board Diagnostic (OBD-II) port, appropriate security schemes should be applied. In this paper, we propose a scheme to embed data integrity and confidentiality into the original FlexRay data frames and reuse the Cyclic Redundancy Check (CRC) field of existing FlexRay data frame to implement data integrity, which does not require to modify the current FlexRay protocol. We select a recently invented lightweight authenticated encryption scheme, AEGIS [5], to protect the dynamic frames, which achieves a shorter latency. We apply AES-CCM (Counter with CBC-MAC (CCM) [1]) to protect the static frames, whose latency is not stringent. We achieve a real-time 32-bit Message Authentication Code (MAC) for the static frames and an offline 64-bit MAC for the dynamic frames. In addition, we propose a unified architecture for implementing both AES-CCM and AEGIS, which reduces the required hardware resources. The experimental results show that our proposed design can achieve 3.71 Gbits/s and 9.44 Gbits/s for computing AES-CCM and AEGIS on automotive-grade XA Zynq-700 all programmable SoCs (XC7Z020), respectively. Compared to the state-of-the-art work of AES-CCM, our proposed design reduces 17.98% clock cycles.1