Research On Key Issues In Cybersecurity Of Intelligent Connected Vehicles

Intelligent connected vehicle is a synthesis of advanced technologies such as the new generation of communication technology,sensing technology,artificial intelligence technology and big data technology.It has typical characteristics of intelligent,connected and electrified.The development of related technologies promotes the rapid change of the global automotive industry.China has made the overall goal and strategy of intelligent car development,and it is scheduled to complete the establishment of technical and industrial system of intelligent connected vehicles in 2035.The automotive industrial ecosystem as well as the intelligent level of vehicles will be continuously improved,and highly automated vehicles will be used on a large scale.With the rapid industrial and technological changes,intelligent connected vehicles are facing more and more serious cybersecurity threats and challenges.In recent years,the rapid development of cybersecurity technology for intelligent connected vehicles has posed a comprehensive challenge to the existing cybersecurity technologies when using these technologies into the automotive industry.From the perspective of research and development management system,it involves the cybersecurity life cycle of automotive,and from the perspective of technology,it is needed to meet the cybersecurity requirements of the new generation of automotive electronic/electrical and software architecture,as well as diversified security-related applications and scenarios such as autonomous driving,OTA(Over The Air,namely remote software upgrade),and vehicle-road collaboration.On the other hand,a series of international and domestic regulations and standards have been issued,and cybersecurity compliance has become an inevitable requirement for the intelligent connected automotive industry.Based on the overall and systematic view of the cybersecurity life cycle of intelligent connected vehicles,this dissertation studies the relevant key technologies involved in the concept stage,development stage and verification stage of this life cycle,including the cybersecurity threat model and risk assessment technology of intelligent connected vehicle,vehicle level cybersecurity key technologies like on-board secure communication and intrusion detection,component level cybersecurity key technologies like security hardening of embedded code and software formal verification.These aforementioned technologies are studied in combination with multi-dimensional characteristics and requirements of intelligent connected vehicle in electronic,electrical and network structure,hardware and software architecture of on-board devices,as well as their available resources,processing performance,application scenarios and so on.The main contributions in this dissertation are as follows.(1)Tightly combined with the features of the electronic and electrical architecture of intelligent connected vehicles,the V model of their life cycle,typical businesses and the requirements of relevant standards,this dissertation puts forward a set of structured cybersecurity threat model of intelligent connected vehicles,including a three-dimension structure of "assets-threats-security attributes",and a specific threat analysis and risk assessment process suitable for components and vehicle level functions or business.At the level of cybersecurity related business FOTA(Firmware Over The Air,firmware remote upgrade)is taken as an example to carry out the application of the model,and at the level of cybersecurity related components T-BOX(Telematics box,a kind of external communication component of intelligent connected vehicles)is taken as the example to carry out the test.On this basis,the threat analysis and risk assessment is efficiently accomplished for the vehicle covering multiple vehicle-level intelligent and connected businesses and key components,as the result the cybersecurity requirements for the vehicle and its components are accurately derived,which provides a good basis for the cybersecurity lifecycle of automotives as well as for the subsequent research.(2)Aiming at the security requirements of authenticity,integrity,anti-replay and other aspects of vehicle on-board communication,this dissertation studies the secure communication technology adapted to CAN/CANFD and on-board Ethernet,so as to provide security guarantee for the internal communication messages of vehicles.The architecture and distributed deployment strategy of vehicle on-board secure communication components are given.The critical technologies and related functional modules of secure communication are researched and implemented.Based on threat analysis and risk assessment,communication signals that need security hardening are screened to provide deployment strategies and methods for the application of secure communication technologies.A comprehensive efficiency evaluation method for secure communication schemes is proposed.All above mentioned aspects constitute a complete solution for architecture design,core function realization,application strategy and comprehensive evaluation of vehicle secure communication.(3)Based on automotive electronic and electrical architecture,on-board network types and intrusion detection requirements,and combined with differences in network protocols,hardware and software resources of associated devices and security events,different types of intrusion detection functions like CAN IDS,Ethernet IDS,NIDPS,HIDPS are formed.These intrusion detection functions can be deployed distributedly and differentiatedly,which has a comparative advantage in performance as well as the ability to cooperate with cloud VSOC platform to realize security management of vehicles.The classification method for malicious traffic in the case of encrypted communication data is studied,aiming at improving the detection ability of vehicle on-board intrusion detection system.The detection method of malicious encrypted traffic is based on a machine learning algorithm combined with domain knowledge,and the training time and accuracy of the model which combines host-level features and stream-level features are improved in this research.(4)With respect to the limited hardware and software resources and high real-time requirements of automotive embedded devices,an automatic C code obfuscation technology independent of hardware platform is researched and implemented.A multi-dimensional comprehensive evaluation model covering security effectiveness,functional consistency,space cost and time cost is proposed.Code confusion experiments are carried out on typical embedded control devices of vehicle and the model is used for evaluation.The results show that the code security hardening method is effective for embedded vehicle devices,as well as the applicability of the proposed model.(5)Embedded real-time kernel is the software core and key of a vehicle control system,and its formal verification is required by some safety and security related standards.Based on the features of the embedded processor architecture and the real-time kernel of a typical vehicle control system,this dissertation studies the formal modeling and verification technology for the kernel.The kernel has safety and security related features like isolation of memory space,isolation of trusted and non-trusted applications,etc.Modeling the kernel considers fine-grained security features in data storage and code execution,extends the C-IL/CC-IL state model,establishes an abstract state space of a vehicle ECU system and defines the semantics of kernel functions,as well as the theorm of implementation correctness of the kernel.Further more,the simulation relations in the 3-layer state space and the realization invariants of the kernel are defined.As the result a feasible application path of formal methodology for similar software is explored and demostrated,supporting to establish highly-trusted core software of vehicle control that satisfies related standards.The formal method studied in this dissertation has good promotion significance.