SCAN-C: a lightweight cryptographic algorithm to secure CAN communications in modern vehicles

Abstract

A controller area network (CAN, ISO-11898:2003) is the central nervous system of contemporary, high-tech vehicles, which links electronic control units (ECUs) to offer a distinctive driving experience through data communication. We propose a lightweight cryptographic algorithm SCAN-C with a unique architecture to secure data communication over the CAN bus in contemporary vehicles. It is a 64-bit block cipher supporting a 160-bit primary key with 12 iterative rounds. The proposed algorithm has a unique hybrid architecture with two structural combinations. The key generation schedule has multiplexers, linear feedback shift registers, and a nonlinear function. The encryption schedule has a Feistel and uniform substitution-permutation network. The decryption schedule is the same as the encryption, with keys applied in reverse order. The innovative architecture of SCAN-C exhibits low consumption of resources (1197 gate equivalents to implement in hardware), better security with low iterative rounds, and optimal energy efficiency. The experimental results suggest that the SCAN-C is suitable for implementation in hardware and software.