A Review of Security Aspects in Vehicular Ad-Hoc Networks
---
paper_title: Cooperative Adaptive Cruise Control Using Turn Signal for Smooth and Safe Cut-In

paper_content:

This paper proposes a method to reduce the risk of collision in cut-in situations, which enhances the performance of Cooperative Adaptive Cruise Control (CACC) in terms of safety. In the proposed control method, the turn signal of the cut-in vehicle is used to create a virtual vehicle such that the cut-in is handled smoothly and safely in advance. This method increases the safety of the CACC system in cut-in situations with a platoon of vehicles.
---
paper_title: Impact on Congestion and Fuel Consumption of a Cooperative Adaptive Cruise Control System with Lane-Level Position Estimation

paper_content:

In recent years, vehicular communications systems have evolved and allowed for the improvement of adaptive cruise control (ACC) systems to make them cooperative (cooperative adaptive cruise control, CACC). Conventional ACC systems use sensors on the ego-vehicle, such as radar or computer vision, to generate their behavioral decisions. However, by having vehicle-to-X (V2X) onboard communications, the need to incorporate perception in the vehicle is drastically reduced. Thus, in this paper a CACC solution is proposed that only uses communications to make its decisions with the help of previous road mapping. At the same time, a method to develop these maps is presented, combining the information of a computer vision system to correct the positions obtained from the navigation system. In addition, the cut-in and cut-out maneuvers for a CACC platoon are taken into account, showing the tests of these situations in real environments with instrumented vehicles. To show the potential of the system in a larger-scale implementation, simulations of the behavior are provided under dense traffic conditions where the positive impact on the reduction of traffic congestion and fuel consumption is appreciated.
---
paper_title: A Review on Security Related Aspects in Vehicular Adhoc Networks

paper_content:

Vehicular Adhoc Network is a special form of the Mobile Adhoc Network which has received remarkable attention with the growing era. It is capable of providing data communication between the mobile vehicles. It focuses on safety related applications and Internet accessing related applications. The basic model of the VANETs consists of On Board Units (OBUs) and Road Side Units (RSUs). These units communicate through an open wireless medium, creating a threat to the network. As the malicious node can attack the privacy information such as the user's identity, tracing preferences etc., if the node is not properly protected. Therefore, there is a need of security requirements to secure it. The paper describes various requirements, characteristics, challenging issues and techniques of security in VANETs. In this paper a theoretical analysis of different security techniques of Vehicular Adhoc Networks has been done which compare different schemes at different levels like hardware, authentication, privacy and certification techniques etc.
---
paper_title: A novel secure communication scheme in vehicular ad hoc networks

paper_content:

Vehicular networks are very likely to become the most pervasive and applicable of mobile ad hoc networks in this decade. Vehicular Ad hoc NETwork (VANET) has become a hot emerging research subject, but few academic publications describing its security infrastructure. In this paper, we review the secure infrastructure of VANET, some potential applications and interesting security challenges. To cope with these security challenges, we propose a novel secure scheme for vehicular communication on VANETs. The proposed scheme not only protects the privacy but also maintains the liability in the secure communications by using session keys. We also analyze the robustness of the proposed scheme.
---
paper_title: A Review on the Various Security Techniques for VANETs

paper_content:

Vehicular systems (VANETs) are a developing research area with an extensive number of utilization cases. Anticipated applications incorporate safety applications, infotainment services, etc. VANETs connect vehicle into a huge mobile ad hoc network share data on a bigger scale. The attributes of VANET posture both difficulties and opportunities in accomplishing security objectives. Giving security to VANET is essential in terms of giving client validation, anonymity, honesty and protection of information. In this paper we have talked about the different techniques related to security in VANET. After going through all the techniques, a comparison has been made between the various techniques and the security concerns.
---
paper_title: OSI Reference Model - The ISO Model of Architecture for Open Systems Interconnection

paper_content:

Considering the urgency of the need for standards which would allow constitution of heterogeneous computer networks, ISO created a new subcommittee for Open Systems Interconnection (ISO/TC97/SC16) in 1977. The first priority of subcommittee 16 was to develop an architecture for open systems interconnection which could serve as a framework for the definition of standard protocols. As a result of 18 months of studies and discussions, SC16 adopted a layered architecture comprising seven layers (Physical, Data Link, Network, Transport, Session, Presentation, and Application). In July 1979 the specifications of this architecture, established by SC16, were passed under the name of OSI Reference Model to Technical Committee 97 Data Processing along with recommendations to start officially, on this basis, a set of protocols standardization projects to cover the most urgent needs. These recommendations were adopted by TC97 at the end of 1979 as the basis for the following development of standards for Open Systems Interconnection within ISO. The OSI Reference Model was also recognized by CCITT Rapporteur's Group on Layered Model for Public Data Network Services. This paper presents the model of architecture for Open Systems Interconnection developed by SC16. Some indications are also given on the initial set of protocols which will likely be developed in this OSI Reference Model.
---
paper_title: Secure Vehicular Communication Systems: Implementation, Performance, and Research Challenges

paper_content:

Vehicular communication systems are on the verge of practical deployment. Nonetheless, their security and privacy protection is one of the problems that have been addressed only recently. In order to show the feasibility of secure VC, certain implementations are required. we discuss the design of a VC security system that has emerged as a result of the European SeVe-Com project. In this second article we discuss various issues related to the implementation and deployment aspects of secure VC systems. Moreover, we provide an outlook on open security research issues that will arise as VC systems develop from today's simple prototypes to full-fledged systems.
---
paper_title: Secure Vehicular Communication Systems: Design and Architecture

paper_content:

Significant developments have taken place over the past few years in the area of vehicular communication systems. Now, it is well understood in the community that security and protection of private user information are a prerequisite for the deployment of the technology. This is so precisely because the benefits of VC systems, with the mission to enhance transportation safety and efficiency, are at stake. Without the integration of strong and practical security and privacy enhancing mechanisms, VC systems can be disrupted or disabled, even by relatively unsophisticated attackers. We address this problem within the SeVeCom project, having developed a security architecture that provides a comprehensive and practical solution. We present our results in a set of two articles in this issue. In this first one, we analyze threats and types of adversaries, identify security and privacy requirements, and present a spectrum of mechanisms to secure VC systems. We provide a solution that can be quickly adopted and deployed. In the second article we present our progress toward the implementation of our architecture and results on the performance of the secure VC system, along with a discussion of upcoming research challenges and our related current results.
---
paper_title: RAISE: An Efficient RSU-Aided Message Authentication Scheme in Vehicular Communication Networks

paper_content:

Addressing security and privacy issues is a prerequisite for a market-ready vehicular communication network. Although recent related studies have already addressed most of these issues, few of them have taken scalability issues into consideration. When the traffic density becomes larger, a vehicle cannot verify all signatures of the messages sent by its neighbors in a timely manner, which results in message loss. Communication overhead as another issue has also not been well addressed in previously reported studies. To deal with these issues, this paper introduces a novel RSU-aided messages authentication scheme, called RAISE. With RAISE, roadside units (RSUs) are responsible for verifying the authenticity of the messages sent from vehicles and for notifying the results back to vehicles. In addition, our scheme adopts the k-anonymity approach to protect user identity privacy, where an adversary cannot associate a message with a particular vehicle. Extensive simulations are conducted to verify the proposed scheme, which demonstrates that RAISE yields much better performance than any of the previously reported counterparts in terms of message loss ratio and delay.
---
paper_title: An Efficient Message Authentication Scheme for Vehicular Communications

paper_content:

In this paper, we introduce a novel roadside unit (RSU)-aided message authentication scheme named RAISE, which makes RSUs responsible for verifying the authenticity of messages sent from vehicles and for notifying the results back to vehicles. In addition, RAISE adopts the k- anonymity property for preserving user privacy, where a message cannot be associated with a common vehicle. In the case of the absence of an RSU, we further propose a supplementary scheme, where vehicles would cooperatively work to probabilistically verify only a small percentage of these message signatures based on their own computing capacity. Extensive simulations are conducted to validate the proposed scheme. It is demonstrated that RAISE yields a much better performance than previously reported counterparts in terms of message loss ratio (LR) and delay.
---
paper_title: Architecture for Secure and Private Vehicular Communications

paper_content:

The deployment of vehicular communication (VC) systems is strongly dependent on their security and privacy features. In this paper, we propose a security architecture for VC. The primary objectives of the architecture include the management of identities and cryptographic keys, the security of communications, and the integration of privacy enhancing technologies. Our design approach aims at a system that relies on well-understood components which can be upgraded to provide enhanced security and privacy protection in the future. This effort is undertaken by SeVeCom (http://www.sevecom.org), a transversal project providing security and privacy enhancing mechanisms compatible with the VC technologies currently under development by all EU funded projects.
---
paper_title: A survey on Intrusion Detection Systems and Honeypot based proactive security mechanisms in VANETs and VANET Cloud

paper_content:

Abstract Vehicular ad-hoc Network (VANET) is an emerging type of Mobile ad-hoc Networks (MANETs) with excellent applications in the intelligent traffic system. Applications in VANETs are life critical since human lives are at stake and therefore, interaction among nodes (vehicles) must be established in the most secure manner. To provide security for VANETs, various security measures are designed, the most popular of which is Intrusion Detection Systems (IDSs). IDS has already proved its worth in detection of malicious nodes in traditional networks but applying the IDS in VANET like networks is somehow different and difficult due to its peculiar characteristics such as resource-constrained nodes, high mobility of nodes, specific protocols stacks, and standards. This paper presents a brief introduction about the various IDSs, in general, to get the readers well acquainted with the concept of IDS after which an in-depth survey of various IDSs that are propounded for VANETs is put forward followed by analyzing and comparing each technique along with merits and demerits. Some basic instructions have also been presented for developing IDSs that have a potential application in VANET and VANET Cloud. Our aim is to identify leading trends, open challenges, and future research directions in the deployment of IDS in VANET. In order to bridge the research gaps in terms of performance, detection rate and overhead, and also to overcome the challenges of existing IDS in literature, a proactive bait based Honeypot optimized IDS system is also proposed with the aim to detect existing and zero-day attacks with minimal overhead. Finally, some open research works being carried out in the field is also proposed.
---
paper_title: A Novel Approach to Enhance the Physical Layer Channel Security of Wireless Cooperative Vehicular Communication Using Decode-and-Forward Best Relaying Selection

paper_content:

This paper proposes a novel approach to enhance wireless vehicle-to-vehicle channel-secrecy capacity by imposing signal transmission diversity. This work exploits cooperative vehicular relaying to extract the associated underlying multipath and Doppler diversity using precoding techniques. We evaluated the capacity and diversity gain for the presented approach to ensure its effectiveness and efficiency. The abundance of moving vehicles, operating in an ad hoc fashion, can eliminate the need to establish a dedicated relaying infrastructure. A relay selection scheme is deployed, taking advantage of the potentially large number of available relaying vehicles. Further, we derivate a closed-form mathematical expression for the channel-secrecy capacity, diversity order gain, and the intercept probability. We used the direct transmission scenario as a reference to assess our analysis. Our analytical and simulation results for the presented model showed that channel-secrecy capacity and performance-indicators improved significantly.
---
paper_title: Learning-Based Rogue Edge Detection in VANETs with Ambient Radio Signals

paper_content:

Edge computing for mobile devices in vehicular ad hoc networks (VANETs) has to address rogue edge attacks, in which a rogue edge node claims to be the serving edge in the vehicle to steal user secrets and help launch other attacks such as man-in-the-middle attacks. Rogue edge detection in VANETs is more challenging than the spoofing detection in indoor wireless networks due to the high mobility of onboard units (OBUs) and the large-scale network infrastructure with roadside units (RSUs). In this paper, we propose a physical (PHY)- layer rogue edge detection scheme for VANETs according to the shared ambient radio signals observed during the same moving trace of the mobile device and the serving edge in the same vehicle. In this scheme, the edge node under test has to send the physical properties of the ambient radio signals, including the received signal strength indicator (RSSI) of the ambient signals with the corresponding source media access control (MAC) address during a given time slot. The mobile device can choose to compare the received ambient signal properties and its own record or apply the RSSI of the received signals to detect rogue edge attacks, and determines test threshold in the detection. We adopt a reinforcement learning technique to enable the mobile device to achieve the optimal detection policy in the dynamic VANET without being aware of the VANET model and the attack model. Simulation results show that the Q-learning based detection scheme can significantly reduce the detection error rate and increase the utility compared with existing schemes.
---
paper_title: Privacy-aware access control for message exchange in vehicular ad hoc networks

paper_content:

Vehicular ad hoc networks are a promising and increasingly important paradigm. Their applications range from safety enhancement to mobile entertainment services. However, their deployment requires several security issues to be resolved, particularly, since they rely on insecure wireless communication. In this paper, we propose a cryptographic-based access control framework for vehicles to securely exchange messages in a controlled fashion by integrating moving object modeling techniques with cryptographic policies. To our knowledge, this is the first time a comprehensive framework for access control in VANETs is proposed.
---
paper_title: An ICI-Aware Approach for Physical-Layer Network Coding in Time-Frequency-Selective Vehicular Channels

paper_content:

Applying physical-layer network coding (PNC) to vehicular ad-hoc networks (VANETs) can theoretically boost the network throughput by 100%, thus partially addressing the intermittent node connectivity and short contact time issues caused by high speed vehicle motions. However, the application of OFDM modulated PNC in VANETs faces detrimental effects caused by carrier frequency offsets (CFOs) and time-frequency-selective channels. CFOs may destroy the orthogonality of OFDM subcarriers, resulting in inter-carrier interference (ICI). The CFOs of two transmitters may also be different, and cannot be removed by CFO tracking and equalization at the receiver as in conventional single-user communication even if the CFOs are known. In addition, time-frequency- selective channels due to delay and Doppler spreads are difficult to estimate and non-accurate channel estimations will increase the detection bit error rate (BER). To address the two challenges, this paper proposes an ICI-aware approach that jointly exploits pilot and data for channel estimation and data detection. Specifically, our approach jointly uses the belief propagation (BP) algorithm to mitigate the CFO/ICI effect for data detection, and the expectation maximization (EM) algorithm to accurately estimate the channels. A linear interpolation method and an ICI compensation method are simulated as benchmarks. Simulation results indicate that our approach improves the BER performance compared to the two benchmarks (more than 2 dB SNR gain in most cases), especially in the high SNR regime.
---
paper_title: An improved certificateless aggregate signature scheme without bilinear pairings for vehicular ad hoc networks

paper_content:

Abstract Certificateless aggregate signature (CL-AS) is a digital signature technique used to achieve improved performance in resource-constrained environments like vehicular ad hoc networks (VANETs) by eliminating the certificate issue in the traditional public key cryptography (PKC), addressing the key escrow problem in identity-based PKC, and utilizing the efficiency benefits of aggregate signature. Recently, an efficient CL-AS scheme for VANETs was proposed which the authors claimed to be existentially secure against forgery attacks in the random oracle model. In this paper, the scheme was analyzed and found to be insecure under existing security model. Consequently, we propose a new efficient certificateless aggregate signature scheme for VANETs applications based on elliptic curve cryptography. The proposed scheme does not only meet the privacy and security requirements for VANETs, but supports batch verification, autonomy, and conditional privacy preservation. In addition, the proposed scheme is provably secure against existential forgery on adaptive chosen message attack in the random oracle model based on the hardness assumption of the elliptic curve discrete logarithm problem. Extensive efficiency analysis demonstrates that the performance of the proposed scheme exceeds those of the recent related schemes in terms of computation cost and communication overhead.
---
paper_title: Computationally Efficient Privacy Preserving Anonymous Mutual and Batch Authentication Schemes for Vehicular Ad Hoc Networks

paper_content:

In the near future, it is envisioned that vehicular Ad hoc networks (VANETs) will be making use of long-distance communication techniques, such as cellular networks and Worldwide Interoperability for Microwave Access (WiMAX), to get instant Internet access for making the communication between vehicles and fixed road side infrastructure. Moreover, VANETs will also make use of short-distance communication methods, such as Dedicated Short-Range Communications (DSRC) and Wireless Fidelity (Wi-Fi) to perform short range communication between vehicles in an ad hoc manner. This Internet connection can provide facility to other vehicles to send traffic related messages, collisions, infotainment messages other useful safety alerts. In such a scenario, providing authentication between vehicle to infrastructure and vehicle to vehicle is a challenging task. In order to provide this facility, in this paper, we propose a computationally efficient privacy preserving anonymous authentication scheme based on the use of anonymous certificates and signatures for VANETs in making them an important component of Internet of Things (IoT) and the development of smart cities. Even though there are several existing schemes available to provide such anonymous authentication based on anonymous certificates and signatures in VANETs, the existing schemes suffer from high computational cost in the certificate revocation list (CRL) checking process and in the certificate and the signature verification process. Therefore, it is not possible to meet the requirement of verifying a large number of messages per second in VANETs which would lead to increased message loss. Hence, we use a computationally efficient anonymous mutual authentication scheme to validate the message source as well as to ensure the integrity of messages along with a conditional tracking mechanism to trace the real identity of misbehaving vehicles and revoke them from VANET in the case of dispute. In this paper, we also introduce an efficient anonymous batch authentication protocol to be used in IoT for Road Side Units (RSUs) to authenticate multiple vehicles simultaneously rather than one after the other such that the total authentication time can be dramatically reduced. This proposed scheme is implemented and the performance analysis shows that our scheme is more efficient in terms of certificate and signature verification cost, while preserving conditional privacy in VANETs.
---
paper_title: Secure and privacy-aware traffic information as a service in VANET-based clouds

paper_content:

The multitude of applications and services in Vehicular Ad hoc NETwork (VANET) and cloud computing technology that are dreamed of in the near future, are visible today. VANET applications are set to explode in the next couple of years as a result of the advancements in the wireless communication technologies and automobile industry. Nevertheless, it is speculated that future high-end vehicles will potentially under-utilize their on-board storage, computation, and communication resources. This phenomenon sets the ground for the evolution of traditional VANET to a rather more applications-rich paradigm referred to as VANET-based clouds. In this paper, we aim at a framework of VANET-based clouds namely VANET using Clouds (VuC) and propose a novel secure and privacy-aware service referred to as Traffic Information as a Service (TIaaS) atop the cloud computing services stack. TIaaS provides vehicles (more precisely subscribers) with fine-grained traffic information from the cloud as a result of subscribers' cooperation with the cloud in a privacy-preserving way. Legitimate VANET users share their frequent whereabouts information referred to as Mobility Vectors (MV) with the cloud infrastructure through gateways (static Road Side Units-RSUs and mobile vehicles with 3/4 G Internet). The gateways forward coarse-grained traffic information (MVs) from vehicles to the cloud whereas after processing, cloud modules construct and re-forward the fine-grained traffic information along with location-based warnings to the subscribers based on their physical locations and moving directions. The communication among vehicles, gateways, and the cloud infrastructure is carried out in a privacy-preserving way. More precisely vehicles share their MVs with cloud infrastructure anonymously. The MVs are hard to link to the sender, until and unless necessary, otherwise. Similarly every vehicle receives fine-grained traffic information in a privacy-preserving manner. The proposed TIaaS keeps the adversaries at bay from abusing users' privacy and/or constructing profiles against targeted users. Moreover for location confidentiality and privacy, we also propose a novel location-based encryption technique that keeps the insider and outsider adversaries at bay from manipulating the contents of the message. Furthermore, the proposed TIaaS preserves conditional privacy and with the help of an efficient revocation mechanism, revocation authorities can revoke any node in case of a dispute. The proposed TIaaS also introduces the thin-client concept for vehicles where most of the time-consuming processing is offloaded to the cloud and the processing resources of the vehicles can be used elsewhere, for instance for the critical safety related applications. More precisely the cloud processes the big traffic data (BTD) and produces timely, decisive, and meaningful results.
---
paper_title: Extended 3PAKE authentication scheme for value-added services in VANETs

paper_content:

Abstract An authentication scheme is inevitable for providing secured communication in high-speed networks like Vehicular Ad-hoc Networks (VANETs), where node speed varies between 10 and 40 m/s. The existing authentication schemes providing value-added services in VANETs face many issues such as invalid service requests, Denial of Service (DoS) attacks, verification failures, high transmission overhead and high verification delay. To deal with the exiting issues, an Extended Three Party Password based Authenticated Key Exchange (E-3PAKE) scheme is proposed in the paper. The E-3PAKE has priority based application services that addresses the security and performance issues in existing schemes. The scheme renders a server-client authentication process and batch message dispatch to improve the efficiency of value-added services. The formal analysis done ensures the security enhancement of the scheme and the simulation results prove that the proposed scheme outperforms the existing schemes with respect to transmission overhead, verification and service response delay.
---
paper_title: Conditional Privacy-Preserving Authentication Using Registration List in Vehicular Ad Hoc Networks

paper_content:

Vehicular ad hoc networks (VANETs) have increased in popularity in recent years and play an extremely important role in the intelligent transportation field. However, the demands of larger communication networks and the integrated message verification process for ensuring security incur more communication and computation overheads, and directly affect the efficiency of existing VANET schemes. To address this issue, this paper proposes a novel and practical conditional privacy-preserving authentication scheme, which uses the registration list instead of the revocation list to reduce the communication overhead. Specifically, our scheme can prevent malicious vehicles from disrupting the security features of VANETs. Moreover, we do not use the bilinear pairing operation, which is the most complicated operation in modern cryptography, thus significantly reducing the computation overhead and communication overhead. Security and performance analyses demonstrate that our proposed scheme is more secure and efficient than current schemes, and that the proposed scheme is more suitable for VANET deployments.
---
paper_title: V2X security: A case study of anonymous authentication

paper_content:

Abstract Vehicle to Everything (V2X) is the enabling technique for future connected cars. Security is essential to the V2X technology, and privacy is an integral element of V2X security. It has been recognized that privacy preserving/anonymous authentication is a fundamental step towards achieving privacy protection in V2X. We are thus motivated to study anonymous authentication, as a case study of V2X security. Specifically we propose two lightweight anonymous credential schemes for anonymous authentication in V2X: one is under the rationale of “witness update outsourcing”, and is applicable to V2V; the other is suitable for V2I, with the characteristic that a vehicular OBU is enabled to operate entirely on the compact bilinear group. We conduct performance analysis both analytically and empirically, and get promising results.
---
paper_title: A taxonomy and survey of cyber-physical intrusion detection approaches for vehicles

paper_content:

With the growing threat of cyber and cyber-physical attacks against automobiles, drones, ships, driverless pods and other vehicles, there is also a growing need for intrusion detection approaches that can facilitate defence against such threats. Vehicles tend to have limited processing resources and are energy-constrained. So, any security provision needs to abide by these limitations. At the same time, attacks against vehicles are very rare, often making knowledge-based intrusion detection systems less practical than behaviour-based ones, which is the reverse of what is seen in conventional computing systems. Furthermore, vehicle design and implementation can differ wildly between different types or different manufacturers, which can lead to intrusion detection designs that are vehicle-specific. Equally importantly, vehicles are practically defined by their ability to move, autonomously or not. Movement, as well as other physical manifestations of their operation may allow cyber security breaches to lead to physical damage, but can also be an opportunity for detection. For example, physical sensing can contribute to more accurate or more rapid intrusion detection through observation and analysis of physical manifestations of a security breach. This paper presents a classification and survey of intrusion detection systems designed and evaluated specifically on vehicles and networks of vehicles. Its aim is to help identify existing techniques that can be adopted in the industry, along with their advantages and disadvantages, as well as to identify gaps in the literature, which are attractive and highly meaningful areas of future research.
---
paper_title: Trust Aware Support Vector Machine Intrusion Detection and Prevention System in Vehicular Ad hoc Networks

paper_content:

Abstract As a mean to improve safety and convenience on the road, Vehicular Ad Hoc Networks (VANETs) provide various advantages to passengers. However, considering that it is a wireless ad hoc type network, it is usual to see numerous security exploits present in the environment. There are prevention methods as well as responsive solutions for network intrusions; the former is known as Intrusion Detection System (IDS), which monitors and detects potential intrusions that are ongoing in the network. Active network attacks are generally designed to reduce or interrupt availability of the network. Effect of these attackers on the network can be measured by select parameters, which can in turn be used as the main lead for detecting malicious behaviors. In this paper, we propose a complete IDS in VANET using the combination of modified promiscuous mode for data collection and Support Vector Machine (SVM) for data analysis to establish a shared trust value for every vehicle on the network as Trust Aware SVM-Based IDS (TSIDS). This method ensures that the source vehicle or node as well as any intermediate network node is aware of the activity of their next hop and in case of malicious behavior or malfunction, they will respond accordingly to keep the network performance as high as possible.
---
paper_title: An effective misbehavior detection model using artificial neural network for vehicular ad hoc network applications

paper_content:

Vehicular ad hoc network (VANET) is the key enabler for future intelligent transportation systems' applications. Due to its high mobility, VANETs rely on the availability of accurate and reliable mobility information of the vehicles. However, misbehavior in mobility can lead to catastrophic results in both safety and traffic efficiency. Several drawbacks of existing misbehavior detection models designed for VANETs which impacted the performance of the applications and the security solutions altogether. Machine learning has not been studied extensively in misbehavior detection in VANET. In this paper, an effective misbehavior detection model based on machine learning techniques is proposed. The proposed model consists of four main phases: data acquisition, data sharing, analysis and decision making. New features are derived which represent the misbehavior, environment and communication status in order to effectively detect the misbehavior data. By using Artificial Neural Network (ANN) techniques namely the feed forward and the back propagation algorithms, an effective misbehavior classifier is trained based on historical data that contains both attacker and normal traffic data. A real-world traffic dataset namely NGSIM is used to construct and evaluate the proposed model. Results show significant improvement in the effectiveness of the proposed model in comparison with the existing baseline model.
---
paper_title: Securing Information Exchange in VANETs by Using Pairing-Based Cryptography

paper_content:

Vehicular Ad Hoc Networks are mainly implemented to enable the interchange of huge amount of information among vehicles and between vehicles and control entities such as road side units or base stations, providing support for a comfortable and safe driving experience. However, due to the recent proliferation of cybersecurity threats, securing such a critical exchange of information becomes a fundamental prerequisite. In this paper, we propose a novel security scheme based on bilinear pairing-based cryptography to improve the security of the information exchanged in VANETs. Such scheme relies on the Elliptic Curve Discrete Logarithm Problem to provide anonymity and robust security features, and on Message Authentication Codes for verifying the vehicles’ identities. The proposed solution is able to achieve mutual authentication between involved entities and prevent impersonation, replay and insider attacks, at the expense of minimum overhead so that also big-data scale communications can be safely supported...
---
paper_title: Mutual authentication in self-organized VANETs

paper_content:

The practical deployment of vehicular networks is still a pending issue. In this paper we describe a new self-organized method of authentication for VANETs, which allows their widespread, fast and secure implementation. Our proposal does not involve any central certification authority because the nodes themselves certify the validity of public keys of the other nodes. On the one hand we propose an algorithm that each node must use to choose the public key certificates for its local store. On the other hand, we also describe a new node authentication method based on a cryptographic protocol including a zero-knowledge proof that each node must use to convince another node on the possession of certain secret without revealing anything about it, which allows non-encrypted communication during authentication. Thanks to the combination of the aforementioned tools, the cooperation among vehicles can be used for developing several practical applications of VANETs, such as detection and warning about abnormal traffic conditions. One of the most interesting aspects of our proposal is that it only requires existing devices such as smartphones, because the designed schemes are fully distributed and self-organized. In this work we include an analysis of both an NS-2 simulation and a real device implementation of the proposed algorithms, which enables us to extract promising conclusions and several possible improvements and open questions for further research.
---
paper_title: An intelligent approach for building a secure decentralized public key infrastructure in VANET

paper_content:

This paper proposed an efficient decentralized public key infrastructure (PKI) using the concepts of Bayesian Coalition Game (BCG) and Learning Automata (LA). LA are assumed as the players in the game, which coordinate among one another for information sharing. To preserve the confidentiality and integrity of the messages, dynamic coalition among the players of the game is formulated using symmetric key encryption and hash-based message authentication. Also, privacy preservation and certificate revocation are included in the proposed scheme to defend against the misbehaving vehicles. For each action taken by an automaton, its action may be rewarded/penalized by the environment in which it operates. LA update their actions probability matrices by getting the reinforcement signal from the environment. The performance of the proposed scheme is evaluated with respect to various metrics in comparison to the other state-of-the-art existing schemes. The results obtained prove the superiority of the proposed scheme. Learning automata-based secure PKI infrastructure is proposed for VANETs.A dynamic coalition among the players of the game is formed using Bayes Theory.The proposed scheme is resilient with respect to various types of attacks.
---
paper_title: An Anonymous Access Authentication Scheme for VANETs Based on ID-Based Group Signature

paper_content:

As one of the hottest research area in wireless networks, vehicular ad-hoc networks (VANETs) can significantly improve the efficiency of Intelligent Transportation System (ITS) and life safety. However, VANETs have to face some security issues and challenges. The security of message transmission and privacy protection during communication still present practical concerns to the deployment of VANETs. Anonymous authentication is one of the key security requirements in VANETs. Though many authentication approaches have been proposed, the scheme that can achieve both security and efficiency is still needed. In this paper, we propose a novel efficient secure authentication scheme through the combination of group signature and identity based (ID-based) signature. The complete anonymous authentication process is elaborated. We also employ pseudonyms mechanism to ensure privacy preservation during authentication. It can be analyzed and proved that our proposed scheme can meet the security and efficiency requirements of VANETs well.
---
paper_title: RSU-Based Distributed Key Management (RDKM) For Secure Vehicular Multicast Communications

paper_content:

Although lots of research efforts have focused on group key management (GKM) for secure multicast, existing GKM schemes are inadequate for vehicle communication (VC) systems since they incur unnecessary rekeying overhead without considering the characteristics of VC systems such as Vehicle-to-Infrastructure communications and a great number of high mobility vehicles. Therefore, we propose a GKM scheme, called RSU-based decentralized key management (RDKM), dedicated for the multicast services in the VC systems. The RDKM scheme significantly reduces the rekeying overhead through delegating a part of the key management functions to the road-side infrastructure units (RSUs) and through updating the key encryption keys (KEKs) within a RSU. The performance of the RDKM scheme is analyzed in terms of communication overhead and storage overhead each of which has a strong impact on the performance of GKM. Furthermore, we propose an optimization algorithm that minimizes the weighted sum of the communication and the storage overhead, called the GKM overhead (GKMO), by appropriately determining the design parameters. The numerical results from the extensive analysis demonstrate that the RDKM scheme outperforms the existing GKM schemes in terms of the GKMO.
---
paper_title: Mitigating DoS Attacks Against Pseudonymous Authentication Through Puzzle-Based Co-Authentication in 5G-VANET

paper_content:

The upcoming Fifth Generation (5G) networks can provide ultra-reliable ultra-low latency vehicle-to-everything for vehicular ad hoc networks (VANET) to promote road safety, traffic management, information dissemination, and automatic driving for drivers and passengers. However, 5G-VANET also attracts tremendous security and privacy concerns. Although several pseudonymous authentication schemes have been proposed for VANET, the expensive cost for their initial authentication may cause serious denial of service (DoS) attacks, which furthermore enables to do great harm to real space via VANET. Motivated by this, a puzzle-based co-authentication (PCA) scheme is proposed here. In the PCA scheme, the Hash puzzle is carefully designed to mitigate DoS attacks against the pseudonymous authentication process, which is facilitated through collaborative verification. The effectiveness and efficiency of the proposed scheme is approved by performance analysis based on theory and experimental results.
---
paper_title: A RSU-aided distributed trust framework for pseudonym-enabled privacy preservation in VANETs

paper_content:

Vehicular ad hoc networks (VANETs) have the potential to change the way of people drive, travel and so on, in which vehicle can broadcast and forward the message of road condition or emergency. When the received messages are unreliable, they may lead the vehicles to make wrong decisions. To assess how trustworthy the messages are, every vehicle holds the reputation value in the trust-based schemes. In pseudonym-based schemes, vehicles change their pseudonyms by some kind of manner to confuse the trackers. However, the reputation value provides an additional clue to track vehicle when it and the pseudonym change asynchronously. To reconcile the conflict of privacy preservation and reputation evaluation, we propose a distributed trust framework for pseudonym-enabled privacy preservation in VANETs. In this framework, the road side unit assigns the reputation label certificate (RLC) to evaluate the reliability of message for every vehicle in its communication range. To preserve the privacy, the RLC manifests two trust statuses to replace the specific reputation value. All the reputation values of vehicles are stored in the centrical database. To encourage vehicle to follow the rules, the reputation update algorithm is designed with different weights, which achieve the reputation value increasing slowly and decreasing quickly. When RLC of vehicle is revoked, its security and privacy will not be protected. Finally, theoretical analysis and simulations show that our scheme can efficiently meet the requirements of security and privacy in VANETs.
---
paper_title: Privacy-Preserving Method for Temporarily Linking/Revoking Pseudonym Certificates in VANETs

paper_content:

Vehicular communication (V2X) technologies are expected to become increasingly common in the future. Although they enable improvements on transportation safety and efficiency, the large scale deployment of V2X requires addressing some challenges. In particular, to prevent abuse by drivers and by the system itself, V2X architectures must: (1) ensure the authenticity of messages, which is usually accomplished by means of digital certification; and (2) preserve the privacy of honest users, so owners of non-revoked certificates cannot be easily identified or tracked by eavesdroppers. A promising design to address these requirements is the Security Credential Management System (SCMS), which is currently among the main candidates for protecting V2X communications in the United States. Even though SCMS provides efficient, scalable and privacy-preserving mechanisms for managing V2X-oriented certificates, in this paper we show that it can be further enhanced. Namely, we present two birthday attacks against SCMS's certificate revocation process, both of which degrade the system's security as time passes and more certificates are revoked. We then describe an alternative design to prevent such security degradation with minimal computational overhead. In complement to these security gains, we also describe a mechanism for improving the flexibility of revocation, allowing certificates (as well as their owner's privacy) to be temporarily revoked in an efficient manner. This functionality is useful, for example, to implement suspension mechanisms or to aid in investigations by law-enforcement authorities.
---
paper_title: Efficient and Scalable Certificate Revocation List Distribution in Hierarchical VANETs

paper_content:

Vehicular ad-hoc networks (VANETs) have become an emerging technology that can fulfill the demand of evolving connected vehicles and growing need for Intelligent Transportation System (ITS). Certificates are used to secure vehicular communication but the certificates of vehicles need to be revoked if any vehicles are found as misbehaving nodes. In VANETs, certificate revocation list (CRL) must be quickly distributed to all vehicular nodes to prevent from undesirable communication with the malicious nodes. However, due to growing number of the certificates, the size of CRL continuously increases, and as a result, it becomes difficult to manage and distribute the CRL in the vehicular networks. In this paper, we present an efficient and scalable scheme to distribute certificate revocation list in the hierarchical architecture of VANETs. Our analysis shows that proposed scheme can distribute certificate revocation list promptly throughout the networks while maintaining low CRL size.
---
paper_title: Mutual authentication in self-organized VANETs

paper_content:

The practical deployment of vehicular networks is still a pending issue. In this paper we describe a new self-organized method of authentication for VANETs, which allows their widespread, fast and secure implementation. Our proposal does not involve any central certification authority because the nodes themselves certify the validity of public keys of the other nodes. On the one hand we propose an algorithm that each node must use to choose the public key certificates for its local store. On the other hand, we also describe a new node authentication method based on a cryptographic protocol including a zero-knowledge proof that each node must use to convince another node on the possession of certain secret without revealing anything about it, which allows non-encrypted communication during authentication. Thanks to the combination of the aforementioned tools, the cooperation among vehicles can be used for developing several practical applications of VANETs, such as detection and warning about abnormal traffic conditions. One of the most interesting aspects of our proposal is that it only requires existing devices such as smartphones, because the designed schemes are fully distributed and self-organized. In this work we include an analysis of both an NS-2 simulation and a real device implementation of the proposed algorithms, which enables us to extract promising conclusions and several possible improvements and open questions for further research.
---
paper_title: Cluster-Based Secure Communication and Certificate Revocation Scheme for VANET

paper_content:

In this paper, Cluster-Based Secure Communication and Certificate Revocation Scheme for VANET is proposed. Initially, the nodes (vehicles) are gathered into various clusters and cluster head (CH) should be selected based on the trusty nodes. The certificate authority (CA) known as the trusted third party is taken into account, however, CA is in charge of revoking and distributing the certificates that belong to the vehicles. The information of the certificate revocation list is provided to the CA. Any cluster member can obtain the details from CH if it identifies valid certificate of the secure transmission of messages that takes place by the application of symmetric cryptography approach, where the encryption and the decryption of certificates may occur. From the simulation result, it is verified that the proposed method shows better performance when compared with the existing works in terms of the delivery ratio, throughput, and latency, etc.
---
paper_title: Efficient, Scalable, and Resilient Vehicle-Centric Certificate Revocation List Distribution in VANETs

paper_content:

In spite of progress in securing Vehicular Communication (VC) systems, there is no consensus on how to distribute Certificate Revocation Lists (CRLs). The main challenges lie exactly in (i) crafting an efficient and timely distribution of CRLs for numerous anonymous credentials, pseudonyms, (ii) maintaining strong privacy for vehicles prior to revocation events, even with honest-but-curious system entities, (iii) and catering to computation and communication constraints of on-board units with intermittent connectivity to the infrastructure. Relying on peers to distribute the CRLs is a double-edged sword: abusive peers could "pollute" the process, thus degrading the timely CRLs distribution. In this paper, we propose a vehicle-centric solution that addresses all these challenges and thus closes a gap in the literature. Our scheme radically reduces CRL distribution overhead: each vehicle receives CRLs corresponding only to its region of operation and its actual trip duration. Moreover, a "fingerprint" of CRL 'pieces' is attached to a subset of (verifiable) pseudonyms for fast CRL 'piece' validation (while mitigating resource depletion attacks abusing the CRL distribution). Our experimental evaluation shows that our scheme is efficient, scalable, dependable, and practical: with no more than 25 KB/s of traffic load, the latest CRL can be delivered to 95% of the vehicles in a region (50x50 KM) within 15s, i.e., more than 40 times faster than the state-of-the-art. Overall, our scheme is a comprehensive solution that complements standards and can catalyze the deployment of secure and privacy-protecting VC systems.
---
paper_title: An Enhanced Distributed Trust Computing Protocol for VANETs

paper_content:

Trust establishment in vehicular ad hoc networks (VANETs) is a challenging task due essentially to the high speed of vehicles, the long distances, and the network topology dynamics. Furthermore, applications context evolves quickly at the same time that the lifetime validity of data messages is short. In this paper, we set up a new distributed trust computing framework tailored to VANETs characteristics and aiming to solve the aforementioned challenges. The proposed framework is based on the investigation of the direct experience between neighboring vehicles without using any recommendation system. We also propose a tier-based messages dissemination technique in order to efficiently detect eavesdropped messages and fake events. Each vehicle checks the authenticity of the received data messages and maintains a trust value for each of its neighbors. We analytically model the trust metrics evolution of malicious vehicles. Extensive simulations are conducted to show the validity of the proposed model and evaluate the efficiency of the proposed trust computing framework.
---

Title: A Review of Security Aspects in Vehicular Ad-Hoc Networks

Section 1: INTRODUCTION
Description 1: Introduce the evolution of autonomous vehicles and the rise in demand for VANETs, emphasizing the importance of V2V and V2I communication, and the cybersecurity challenges they present.

Section 2: RELATED WORK
Description 2: Discuss the development of VANET communication technology, review the state of the art in security, and highlight the importance of standards from different regions.

Section 3: EUROPEAN STANDARD
Description 3: Provide an overview of European standards for intervehicular communications, detailing the security protocols and encryption processes outlined by ETSI.

Section 4: SECURITY
Description 4: Elaborate on the cybersecurity challenges VANETs face, discussing the sensitivity to attacks due to broadcast nature and wireless networks, and review ongoing projects and their contributions.

Section 5: HARDWARE SECURITY
Description 5: Explain hardware-based security solutions, including external encryption/decryption devices, TPD, EDR, and other approaches to prevent spoofing, DoS, and other attacks.

Section 6: AUTHENTICATION
Description 6: Describe authentication processes such as certificates, digital signatures, and trusted lists, and explain the challenges and solutions related to authentication in VANETs.

Section 7: DETECTION AND CORRECTION OF MALICIOUS DATA
Description 7: Discuss the importance of detecting and correcting malicious data, and review various techniques and technologies used to identify security breaches in VANETs.

Section 8: PUBLIC KEY INFRASTRUCTURE
Description 8: Detail the use of public key infrastructure in VANETs, the challenges of key exchange, and proposed solutions to enhance security using PKI.

Section 9: GROUP SIGNATURE
Description 9: Describe the role of group signatures in node authentication, highlighting various approaches and the potential issues related to initial authentication delays.

Section 10: CERTIFYING AUTHORITY
Description 10: Discuss the necessity of certifying authorities in VANETs, various certificate revocation systems, and decentralized approaches to establishing trust in communications.

Section 11: GLOBAL ANALYZE
Description 11: Summarize the current state of VANET security, discussing the progress made, potential gaps, and the need for comprehensive testing of proposed solutions.

Section 12: CONCLUSION 
Description 12: Conclude with reflections on the technologies reviewed, the consensus on certain security elements, and the remaining challenges in achieving robust VANET security.