A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> In the near future, it is expected that vehicles which increasingly become an intelligent systems will be equipped with radio communications interfaces. Thus, vehicular networks can be formed and they are commonly known as VANETs (Vehicular Ad hoc NETworks), a use case of mobile ad hoc networks where cars are the mobile nodes. As VANETs exhibit several unique features such as the high mobility of nodes, short connection times, etc. conventional security mechanisms are not always effective. Consequently, a wide variety of research contributions have been recently presented to cope with the intrinsic characteristics of vehicular communication. This paper provides a summary of the recent state of the art of VANETs, it presents the communication architecture of VANETs and outlines the privacy and security challenges that need to be overcome to make such networks safety usable in practice. It identifies all existing security problems in VANETs and classifies them from a cryptographic point of view. It regroups, studies and compares also the various cryptographic schemes that have been separately suggested for VANETs, evaluates the efficiency of proposed solutions and explores some future trends that will shape the research in cryptographic protocols for intelligent transportation systems. <s> BIB001 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> Cooperative Intelligent Transportation Systems, mainly represented by vehicular ad hoc networks (VANETs), are among the key components contributing to the Smart City and Smart World paradigms. Based on the continuous exchange of both periodic and event triggered messages, smart vehicles can enhance road safety, while also providing support for comfort applications. In addition to the different communication protocols, securing such communications and establishing a certain trustiness among vehicles are among the main challenges to address, since the presence of dishonest peers can lead to unwanted situations. To this end, existing security solutions are typically divided into two main categories, cryptography and trust, where trust appeared as a complement to cryptography on some specific adversary models and environments where the latter was not enough to mitigate all possible attacks. In this paper, we provide an adversary-oriented survey of the existing trust models for VANETs. We also show when trust is preferable to cryptography, and the opposite. In addition, we show how trust models are usually evaluated in VANET contexts, and finally, we point out some critical scenarios that existing trust models cannot handle, together with some possible solutions. <s> BIB002 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> Abstract A vehicular Ad Hoc Network (VANET) is a class of mobile ad hoc network (MANET) which supports, vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communications. The significant features of VANET includes, self-organization, distributed networking, and highly dynamic topology. The VANET features and its applications to road safety have attracted a lot of interest in industry and academia more so into the research on improvement of transportation systems for saving millions of lives. The transmission of messages in open-access environment like VANET leads to the most critical and challenging security issues. Authentication, data confidentiality, data integrity, data availability, and non-repudiation are crucial components of security in VANET. This paper focuses on the authentication schemes in VANET as it plays a important role in secured communication. The authentication schemes are basically classified into three categories: cryptography techniques, digital signatures, and message verification techniques. The main objective of this paper is to provide a taxonomy of authentication schemes, and discuss their mechanisms, advantages, disadvantages, performance and scope of research. Furthermore, the paper concludes with presentation of open security issues in VANET authentication. <s> BIB003 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> In the last few years, increasing attention has been provided to research Vehicle-to-Pedestrian (V2P) communication systems. These V2P systems serve different purposes (safety or convenience) and cater to different Vulnerable Road User (VRU) groups. Also, these V2P systems employ different communication technologies, and use different mechanisms to interact with the users. An effective V2P system also needs to consider varying characteristics of different VRUs. These various elements may be considered as design parameters of the V2P system. In this paper, we discuss such elements and propose a design framework for the V2P system based on them. We also provide an extensive survey of existing V2P efforts for safety and convenience applications and their design considerations. We perform a case study that compares the different approaches of V2P safety system for different VRU groups under different pre-crash scenarios. Finally, we discuss a few technological challenges in integration of VRUs into V2X systems. <s> BIB004 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> Vehicular ad hoc networks (VANETs) are becoming the most promising research topic in intelligent transportation systems, because they provide information to deliver comfort and safety to both drivers and passengers. However, unique characteristics of VANETs make security, privacy, and trust management challenging issues in VANETs’ design. This survey article starts with the necessary background of VANETs, followed by a brief treatment of main security services, which have been well studied in other fields. We then focus on an in-depth review of anonymous authentication schemes implemented by five pseudonymity mechanisms. Because of the predictable dynamics of vehicles, anonymity is necessary but not sufficient to thwart tracking an attack that aims at the drivers’ location profiles. Thus, several location privacy protection mechanisms based on pseudonymity are elaborated to further protect the vehicles’ privacy and guarantee the quality of location-based services simultaneously. We also give a comprehensive analysis on various trust management models in VANETs. Finally, considering that current and near-future applications in VANETs are evaluated by simulation, we give a much-needed update on the latest mobility and network simulators as well as the integrated simulation platforms. In sum, this paper is carefully positioned to avoid overlap with existing surveys by filling the gaps and reporting the latest advances in VANETs while keeping it self-explained. <s> BIB005 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Introduction <s> Abstract The intelligent transportation system (ITS) is made possible and practical due to vehicular ad hoc networks (VANETs) that helps improve drivers safeties and traffic efficiency on road by interchanging traffic-related information among vehicles and infrastructures. However, due to the open wireless access medium, the security and privacy of this information become quite critical in VANETs. The attackers could capture, intercept, alter, replay and delete the traffic-related information and could compromise the security of VANETs. Therefore, to ensure security and privacy of the traffic-related information in VANETs is the hot research area of nowadays. In this context, lots of research works have been done to secure vehicular communications. However, these works did not address the security issues in terms of security requirements, security attacks, and efficiency in performance, properly. In this paper, several authentication and privacy schemes have been classified and discussed their mechanisms, strengths and limitations, security requirements, attacks, and performance parameters. Finally, we identified some open research challenges in the domain of VANETs security. <s> BIB006
In recent years, the new development and enhancement in intelligent transportation systems (ITSs) have gained significant attention from both industry and research communities. The ITS contributes the major part in terms of providing road safety, improving traffic flow, and offering entertainment services on vehicles BIB001 . The automotive industry realizes the need for the vehicles to be connected with the wireless communication system, which enables communication between vehicles and between vehicles and infrastructure. Such communication can significantly increase traffic safety and optimize the traffic flow  . It can also broaden the vehicle recognition events, which, at present, cannot be detected by available electronic sensors and loop detectors. Therefore, embedded sensors have been introduced in which traffic information such as driving behaviors, traffic flow parameters, and driving and security mechanisms in the vehicular network, i.e., VANETs and VANET cloud. This survey outlines the brief introduction of IDSs and discussed their related schemes in detail. Then, they outline the open research challenges in IDS and identify future research directions. In Reference  , Wang et al. presented a survey on vehicle-to-everything (V2X) application requirements and outlines the need of testing challenges along with the brief discussion on testing methods of V2X communication in terms of the architectural point of view. In Reference BIB004 , Sewalker and Seitz have discussed the design parameters of the vehicle-to-pedestrian (V2P) system, and outlined the existing V2P schemes for safety applications and their design considerations, along with the integration challenges of vulnerable road users (VRUs) with the V2X system. Zhaojun et al. BIB005 discussed the recent developments in vehicular networks and outlined the security and privacy issues. This survey discussed the basic architecture and characteristics in VANETs. Then, they discussed the security services along with threats and attacks. Second, the authors described the security and privacy issues along with the trust models in VANETs. Ikram et al. BIB006 launched a survey on authentication and privacy schemes for VANETs in which the authors discussed and classified the security mechanism of these schemes. Then, they indicated some open research issues and security challenges in VANETs. The above surveys comprehensively cover the VANET architecture and security challenges. However, this survey focuses on the VANET security services and authentication schemes in detail. First, we discuss the VANET security services. Second, we present each security service of VANETs in terms of threats and attacks along with the recent state-of-the-art methods that indicate the existing issues of VANET security and its solutions, whereas the authors in References BIB002 BIB003 BIB005 BIB006 did not cover these. Furthermore, we comprehensively cover the authentication schemes in detail, while most of the surveys did not cover the authentication schemes except Reference BIB005 , which explained the authentication schemes in detail. Third, the latest simulation tools and the performance of the authentication schemes in terms of simulation tools were discussed, which was followed by the VANET applications, while most of the surveys did not discuss the simulation tools and its utilization on the authentication schemes along with the VANET applications. Lastly, we identified some open research challenges in VANETs that the researcher may face while conducting the research in order to deploy VANET technologies and services efficiently, while most of the previously mentioned surveys did not discuss the existing research challenges in VANETs. In addition to open research issues, we also identified some possible solutions to deal with these issues along with the future research directions.