Ryo Kurachi

The software-defined vehicle (SDV) is a next-generation automobile whose functions are defined by software, with its architecture shifting towards a zonal structure. In this paper, we first explain the structural differences of SDV from conventional vehicles and the enabling technologies it such as virtualization, microservices, and over-the-air (OTA) updates. We then categorize the expanding cybersecurity threats arising from increased connectivity and supply chain complexity, and discuss specific attack scenarios. Furthermore, we detail multilayered countermeasures, including transparency with Software Bill of Materials (SBOM), ensuring supply chain integrity with Uptane and in toto, and hardware security with HSM/TEE. Finally, we consider industrial challenges and future prospects, such as compliance with international standards like UN-R155 and the establishment of a DevSecOps framework.

Time-sensitive networking (TSN), as a solution to the nondeterministic communication of traditional Ethernet, meets the real-time and deterministic communication requirements of intelligent automobiles. There are three traffic types in intelligent automobiles, including time-triggered (TT) flows, audio-video-bridging (AVB) flows, and best-effort (BE) flows, and TSN proposes the gate control list (GCL) to control the transmission of the above traffic. The current GCL synthesis usually serves the hard real-time TT flows but ignores the delay of non-TT flows; and it introduces guard bands to ensure the noninterference transmission of TT flows, inevitably wasting bandwidth. Therefore, this article proposes a design synthesis and optimization strategy to improve the transmission of AVB flows and bandwidth utilization while ensuring the real-time performance of TT flows. This strategy first adopts the initial time window design to allocate the antecedent time windows for AVB flows, then transmits AVB flows according to the deadline to enhance the scheduling of AVB flows, and finally flexibly adjusts the time windows of TT flows and AVB flows according to the size of AVB flows to improve bandwidth utilization. Experimental results show the effectiveness of the proposed strategy in improving the transmission of AVB flows and bandwidth utilization compared to the state-of-the-art methods.

Time-Sensitive Networking (TSN) realizes high bandwidth and time determinism for data transmission and thus becomes the crucial communication technology in time-critical systems. The Gate Control List (GCL) is used to control the transmission of different classes of traffic in TSN, including Time-Triggered (TT) flows, Audio-Video-Bridging (AVB) flows, and Best-Effort (BE) flows. Most studies focus on optimizing GCL synthesis by reserving the preceding time slots to serve TT flows with the strict delay requirement, but ignore the deadlines of non-TT flows and cause the large delay. Therefore, this paper proposes a comprehensive scheduling method to enhance the real-time scheduling of AVB flows while guaranteeing the time determinism of TT flows. This method first optimizes GCL synthesis to reserve the preceding time slots for AVB flows, and then introduces the Earliest Deadline First (EDF) method to further improve the transmission of AVB flows by considering their deadlines. Moreover, the worst-case delay (WCD) analysis method is proposed to verify the effectiveness of the proposed method. Experimental results show that the proposed method improves the transmission of AVB flows compared to the state-of-the-art methods.

The CAN FD emerges as a promising CAN technology inside the ACPS due to its advantages of high data-phase bit-rate and message payload. HSM based security solution is recommended by auto industry to protect CAN FD from potential security attacks, but it induces new challenges on timing analysis of CAN FD messages, which is left open in the literature. This paper develops the first security-aware system model to describe the processing of CAN FD messages, and presents a new WCRT analysis to bound the interference induced by security-critical messages. We give the theoretical proof that our WCRT analysis can upper bound the response time of CAN FD messages. Using a small message set, we show that the WCRT computed by our new analysis is only 14% percent higher than the true WCRT obtained from an exhaustive search based simulator. By comparing with existing method, the number of impacted messages increases along with the increasing number of security critical messages, and for the two typical CAN FD systems, the percentage of WCRT increase varies from 12.43% to 14.57% and 7.0% to 10.89%, respectively; the percentage of WCRT decrease varies from 3.29% to 6.04% and 4.13% to 7.93%, respectively.

Extensibility is an important optimization objective for the E/E architecture of automotive cyber-physical systems (ACPS), while little attention has paid to the extensibility-aware design of in-vehicle network. To address this problem, this paper formulates a trade-off problem that balances the bandwidth utilization and the extensibility from the initial design of CAN FD. We firstly propose a new extensibility model and the related evaluation metric, and then two optimization algorithms, namely, the mixed integer linear programming (MILP) approach and the simulated annealing (SA) based heuristic approach, are proposed to resolve the trade-off problem for mid-sized and industry sized signal sets, respectively. The experiment results show the efficiency of the proposed extensibility metric and the optimization algorithms. By comparing with state-of-the-art algorithm, the MILP reduces the increase range of the bandwidth utilization of the extended signal set by 18.17% to 57.64% averagely, and 49.22% to 89.40% maximally, with only 0.06% to 0.79% bandwidth utilization overhead; the SA approach can reduces the increase range of the bandwidth utilization of the extended signal set by 12.71% to 58.33% averagely, and 40.08% to 89.40% maximally, with only 0.06% to 0.8% bandwidth utilization overhead.

To realize the optimized design of automotive cyber- physical system, it is required to consider the interplay between communication and computation. However, existing research about the design of CAN with flexible data-rate (CAN FD) ignores this, it only considers the minimization of bandwidth utilization and neglects the fact that it would trigger too many unnecessary message receiving interrupts (MRIs) on message receiving electronic control units (ECUs). To address this prob- lem, this paper formulates a trade-off problem that balances the bandwidth utilization and the number of unnecessary MRIs during the design of CAN FD. We firstly propose an algorithm to analyze the number of unnecessary MRIs triggered by the packed messages, and then two heuristic algorithms, namely, the Top-Down approach and the Hybrid approach, are proposed to resolve the trade-off problem for mid-sized and large signal sets, respectively. The experiment results show that compared with state-of-the-art algorithm, the Top-Down approach reduces the unnecessary MRIs by 10.48% to 99.89% with only 0.02% to 1.32% bandwidth utilization overhead, the Hybrid approach reduces the unnecessary MRIs by 23.15% to 99.63% with only 0.13% to 2.07% bandwidth utilization overhead.

With the considerable growth of cybersecurity risks in modern automobiles, cybersecurity issues in the in-vehicle network environment have attracted significant attention from security researchers in recent years. Enhancing the cybersecurity ability of in-vehicle networks while considering the computing resource and cost constraints become an urgent issue. To address this problem, a novel information entropy-based method is proposed in this paper, which uses a fixed number of messages as sliding windows. By improving the sliding window strategy and optimizing the decision conditions, the detection accuracy is increased and the false positive rate is reduced. Experimental results demonstrate that the proposed method can provide real-time response to attacks with a considerably improved detection precision for intrusion detection in the in-vehicle network environment.

The Controller Area Network with Flexible Data- Rate (CAN FD) is the new generation of CAN technology to meet the daily increasing bandwidth requirement for Automotive Cyber-Physical Systems (ACPS). However, ACPS is a security- critical system, an efficient security/timing-aware Design Space Exploration (DSE) method is required to fully utilize CAN FD's high data phase data-rate. In this paper, we propose an AUTOSAR-compliant system model that integrates both timing and security constraint, an integrated Mixed-Integer Linear Programming formulation (i-MILP) for the optimal DSE of CAN FD, and a divide-and-conquer approach to the i-MILP (dc-MILP) to address its timing complexity problem. The experiment results show that dc-MILP scales well for industrial-size systems, and saves 1.94% to 4.76% bandwidth utilization and guarantees the schedulability for more signal sets by comparing with state-of- the-art algorithm.