Caiba: Multicast Source Authentication for CAN Through Reactive Bit Flipping

IEEE European Symposium on Security and Privacy, pp. 710–719

Abstract

Controller Area Networks (CANs) are the back-bone for reliable intra-vehicular communication. Recent cyberattacks have, however, exposed the weaknesses of CAN, which was designed without any security considerations in the 1980s. Current efforts to retrofit security via intrusion detection or message authentication codes are insufficient to fully secure CAN as they cannot adequately protect against masquerading attacks, where a compromised communication device, a so-called electronic control units, imitates another device. To remedy this situation, multicast source authentication is required to reliably identify the senders of messages. In this paper, we present Caiba, a novel multicast source authentication scheme specifically designed for communication buses like CAN. Caiba relies on an authenticator overwriting authentication tags on-the-fly, such that a receiver only reads a valid tag if not only the integrity of a message but also its source can be verified. To integrate Caiba into CAN, we devise a special message authentication scheme and a reactive bit overwriting mechanism. We achieve interoperability with legacy CAN devices, while protecting receivers implementing the AUTOSAR SecOC standard against masquerading attacks without communication overhead or verification delays.

Authors 5

1. Eric Wagner

   Fraunhofer Institute for Communication, Information Processing and Ergonomics

   Affiliation as printed

   Fraunhofer FKIE,Cyber Analysis & Defense

2. Frederik Basels

   Fraunhofer Institute for Communication, Information Processing and Ergonomics

   Affiliation as printed

   Fraunhofer FKIE,Cyber Analysis & Defense

3. Jan Bauer

   Fraunhofer Institute for Communication, Information Processing and Ergonomics

   Affiliation as printed

   Fraunhofer FKIE,Cyber Analysis & Defense

4. Klaus Wehrle Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,Communication and Distributed Systems

5. Martin Henze Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,Security and Privacy in Industrial Cooperation