  The Controller Area Network (CAN) is considered as the de-facto standard for
the in-vehicle communications due to its real-time performance and high
reliability. Unfortunately, the lack of security protection on the CAN bus
gives attackers the opportunity to remotely compromise a vehicle. In this
paper, we propose a Lightweight Encryption and Authentication Protocol (LEAP)
with low cost and high efficiency to address the security issue of the CAN bus.
LEAP exploits the security-enhanced stream cipher primitive to provide
encryption and authentication for the CAN messages. Compared with the
state-of-the-art Message Authentication Code (MAC) based approaches, LEAP
requires less memory, is 8X faster, and thwarts the most recently proposed
attacks.
