Performance Analysis of the Confidentiality Service in CAN

This paper addresses the security service infrastructure included in the Controller Area Network (CAN), proposing the incorporation of the confidentiality service for that kind of network. Regarding security currently CAN only supports a special kind of service, namely safety, of data transfers for error detection, signaling, and self checking. Nevertheless, as CAN has become more diverse, complex and integrated into other kind of networks, it must provide higher security services, such as confidentiality, quite especially for its bus which is the most attack-prone point on CAN. Taking into account, on one hand, the security services defined by ISO and, on the other hand, the security services defined by CAN, this paper proposes to incorporate the confidentiality service to CAN based on a lightweight symmetric stream cipher algorithm, such as RC4 or A5/1. Finally, this paper presents the performance analysis of both algorithms and recommends using RC4 because it consumes much less clock cycles that A5/1 for encrypting the CAN data frames.