Comprehensive Review of CAN Bus Security: Vulnerabilities, Cryptographic and IDS Approaches, and Countermeasures

Vehicle connectivity environments and advancements in vehicular technologies offer users both functional convenience and safety features, including remote diagnosis and assistance. To enable these capabilities, modern vehicles utilize various automotive serial protocols such as FlexRay, Local Interconnect Network (LIN), and the popular Controller Area Network (CAN). The CAN bus serves as a key protocol for in-vehicle networks (IVNs), facilitating the exchange of vehicle parameters among Electronic Control Units (ECUs). Despite its merits, the CAN bus has been found to have internal and external vulnerabilities. While numerous countermeasures are currently in place, the continuous advancements in vehicular interfaces have introduced new attack vectors, necessitating the development of additional safeguards. Existing research has primarily focused on CAN attacks initiated through direct interfaces, telematics and infotainment systems, and sensors. In this study, we aim to present an adversarial model for the CAN bus while also evaluating cryptographic and Intrusion Detection System (IDS) approaches considering real-time constraints and other relevant variables. Furthermore, we will classify available countermeasures into relevant categories and discuss their effectiveness. By conducting a comprehensive analysis of published works, our goal is to provide a comprehensive overview of CAN-related studies. This includes exploring potential mitigation techniques and identifying new research opportunities for IVNs. The synthesis of this information will offer valuable insights into the current state of CAN security, the challenges it faces, and the directions for future exploration. In summary, our study aims to address the vulnerabilities of the CAN bus, considering both existing and emerging attack vectors. By examining cryptographic and IDS approaches, we will assess their viability in real-time scenarios. Additionally, we will categorize and discuss the effectiveness of available countermeasures. Through this analysis, we strive to provide a holistic understanding of CAN-related research, paving the way for prospective mitigation techniques and identifying new horizons for IVNs.