# A Hybrid-Cryptography Engine for Securing Intra-Vehicle Communications
## 1 Introduction  
When security issues are addressed, it can be observed that connected and automated vehicles are subject to a large number of risks. This is mainly due to the potentially wide attack surface that is exhibited by the large number of heterogeneous mechanical, hardware, and software components and their interconnections. Some recent attack trends are discussed in [1, 2]. In those papers the authors summarize the attack vectors in _Sniffing_, i.e., the ability to intercept unsecured communications over a shared channel _Spoofing_, i.e., the ability for an attacker to establish a communication by faking its identity, _Jamming_, i.e., disrupt the communication by overwhelming the radio channels and _Replay Attacks_, i.e., blind re-transmission of a sniffed communication. Additionally, there is a large number of possible attacks that targets known or, in the worst case unknown, vulnerabilities existing in all the software stacks. Examples can be found in the infotainment software layers [3], and in hardware components, e.g., micro-architural vulnerabilities [4], or in possible exploits in communication protocols. In general, we can state that the smarter and more connected a vehicle is, the more serious consequences are induced when security mechanisms fail: for instance, in terms of electrical or mechanical malfunctions ([[https://cybersecurity.att.com/blogs/security-essential](https://cybersecurity.att.com/blogs/security-essential)]([https://cybersecurity.att.com/blogs/security-essential](https://cybersecurity.att.com/blogs/security-essential)) \(\mathrm{s}/\mathrm{the\text{-}top\text{-}8\text{-}cybersecurity\text{-}threats\text{-}facing\text{-}the\text{-}automotive\text{-} industry\text{-}heading\text{-}into\text{-}2023\) (accessed on 27 November 2023)) and data leakage (Toyota data-leak: [[https://techcrunch.com](https://techcrunch.com)]([https://techcrunch.com](https://techcrunch.com))/2023/05/31/toyota-customer-data-leak-years/?guccounter=1 (accessed on 27 November 2023)). Many efforts can be found in recent years' research in order to protect vehicular communications, in particular in Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), and Vehicle-to-Anything (V2X) scenarios to a large extent. V2X links represent a relevant part of the so-called attack surface of the whole system, and other weak points may be found in the vehicle's on-board architecture. Indeed, modern vehicles are equipped with complex internal networks that connect components, Electronic Control Units (ECUs), electro-mechanical devices, sensors, infotainment systems, etc. Such architectures are evolving from the \"ad-hoc\" concept of VANET (_Vehicular Ad-hoc Network_) into networks that resemble classical computer networks, with all the well-known security issues. In this perspective, a standalone vehicle can be considered a fully-operational complex cyber-physical system requiring an equally complex multi-layered security solution. Neglecting this vision or underestimating its relevance could determine, for example, that an intrusion in any unsecured internal component of the on-board architecture can spread to other ones, potentially causing damage to the vehicle and to the passengers. On the opposite side, considering every internal component as untrustable can bring an unbearable level of complexity in communications that could collide with the computing and communications performance requirements that some critical applications and services may require. Resorting to cryptography-based solutions can help solve security problems; nevertheless, generic cryptographic solutions are often not designed to fit the needs of an intra-vehicle network with ambitious performance and low-latency requirements. Within the context of intra-vehicle networks security, providing state-of-the-art security primitives along with secure and certifiable hardware/software implementations is a non-trivial task, especially when considering robustness performance and communication latencies.