Editorial Security Hardened and Privacy Preserved Vehicle-to-Everything (V2X) Communication

<jats:p />

e authors in a research article titled "Implementation of Blockchain Consensus Algorithm on Embedded Architecture" presented study of the feasibility as well as the gain realized by using an architecture adopted at Ethereum PoW on FPGAs [14]. e concept of finding optimized solutions adapted to the specific constraints of blockchain-based applications such as execution time, number of required nodes, and suitable data security algorithms are heavily researched in the literature. e paper also presents the implementation of an embedded-blockchain approach. is system presents a hybrid implementation of ethereum nodes on Raspberry Pi on one side and of PoW consensus on FPGA. is may prove to be a significant proposal for future implementations since it provides the possibility to set up an ASIC to accelerate the POW execution. e authors in a research article titled "New Efficient and Secured Authentication Protocol for Remote Healthcare Systems in Cloud-IoT" proposed new authentication scheme for health care systems cloud-IoT [15]. Before presenting the proposed work, the authors demonstrate the vulnerabilities and security issues of previous proposed studies including Sharma and Kalra's scheme.
e authors discover few weaknesses in the Sharma and Kalra's protocol along with password guessing and smart card stolen attacks. e simulation tests as performed under Scyther tool confirm that the lightweight proposed protocol satisfies up-to-date security requirements. e formal and informal analysis also validates the findings of the obtained results in the performance evaluation. e authors in a research article titled "Chaotic Reversible Watermarking Method Based on IWT with Tamper  Detection for Transferring Electronic Health Record" presented a reversible and lightweight watermarking method for IoT-based healthcare systems employing integer wavelet transform (IWT) and chaotic maps, which is capable of tamper detection [16]. In this study, the authors demonstrated a secure and lightweight watermarking method having imperceptibility and reversibility impacts, with least possible attacks in IoT-based healthcare systems. As per the results, the proposed scheme took advantage of IWT and reduces greatly the computational complexity as compared to other related techniques. Besides, the scheme supports tamper detection and reversibility and is also provably resistant to several signal processing threats. e research article titled "A Provably Secure Authentication and Key Exchange Protocol in Vehicular Ad Hoc Networks" presents a novel and secure authenticated key agreement scheme to negotiate an agreed session key prior to communicating the confidential information in vehicular ad hoc network (VANET) [17]. In the follow-up of sensing sensitive information, the transmission of information may be affected or tampered due to insecure public wireless channel. erefore, it becomes critical to secure the transmission. In this context, the proposed protocol achieves the objective by supporting mutual authenticity among the three participating entities including RSU, user, and cloud server. Finally, the formal security analysis depicts that the protocol is workable, efficient, and secure. e research article titled "Security in Vehicular Ad hoc Networks: Challenges and Countermeasures" discusses the characteristics and all the possible security limitations including attacks and threats at different protocol layers of the VANETs architecture [18]. Moreover, the paper also surveys different countermeasures. is paper surveys VANET security challenges such as DoS, Sybil, impersonation, replay, and other attacks. Furthermore, it presents the possible countermeasures. e survey may serve as a useful reference for future intelligent transport systems. e research article titled " e Snowden Phone: A Comparative Survey of Secure Instant Messaging Mobile Applications" presents a comprehensive survey on security and privacy analysis of recent and popular instant messaging applications [19]. In this paper, the authors discussed all the necessary prerequisites that a reader needs to do for securing the messaging applications as well as analyzing the mobile applications that help in implementing end-to-end secure messaging. ey define the key characteristics of a secure and privacy-preserving communication protocol for instant messaging apps and then perform an analysis on the most popular ones. Furthermore, the authors perform a comparison on the end-to-end encryption protocols. After the analysis, the authors recommend some possible security improvements for all applications under analysis that provide quite interesting highlights. ey use different testing scenarios to study the security and usability characteristics of secure mobile applications and provide suggestions for improvements. e research article titled "A Reliable Network Intrusion Detection Approach using Decision Tree with Enhanced Data Quality" presents a reliable network intrusion detection approach based on decision tree classifier and engineering feature techniques [20]. In the present research paper, authors proposed a new reliable network intrusion detection approach based on decision tree with improved data quality. e authors employed network data preprocessing and entropy decision-based feature selection to enhance quality of training for building decision tree classifier to boost the quality of intrusion detection. e proposed paper is new and significant because it is based on machine learning algorithm. e experimental study depicts that the contributed approach presents many advantages and shows high accuracy in comparison with other state-ofthe-art models. e research article titled "Internet of ings Security: Challenges and Key Issues" aims to study the key issues including security threats in state-of-the-art IoT-based authentication schemes [21]. Mostly, the paper highlights the current challenges as posed to the induction of IoT devices in the precarious domain. e authors emphasized on securing real and virtual worlds based on IoT technology resulting in secure energy, water management, construction, industry, environment, telecommunications, healthcare, surveillancebased sectors, etc. Mostly, IoT-based networks are prone to Denial of Service (DoS) attack, replay attack, and insider attacks. e authors emphasized on countering the mentioned threats by employing one-time password, ellipticcurve cryptography (ECC), ID-based authentication, and certificate-based authentication solutions. e research article titled "Adaptive Fault-Tolerant System and Optimal Power Allocation for Smart Vehicles in Smart Cities using Controller Area Network (CAN)"aims to analyze the increased energy consumptions and transmission collisions resulting in loss of data packets in a CANbased smart vehicle system [22]. e authors try to find the fault-tolerant capability through probabilistic automatic repeat request (PARQ) and also probabilistic automatic repeat request (PARQ) with fault impact (PARQ-FI) and also provide the optimal power allocation in CAN sensor nodes for enhancing the performance of the system. e simulation results depict an increase packet delivery ratio of the proposed scheme. e promising findings of the proposed system may prove to be a significant reference for future smart cities. e research article titled "Designing an Efficient and Secure Message Exchange Protocol for Internet of Vehicles" aims to present a secure message authenticated key exchange protocol for the exchange of information among legitimate participating members of IoV (SMEP-IoV) [23]. Initially, the author reviewed some of the recently presented authentication protocols for securing IoVs. en, they constructed a symmetric key-oriented authenticated key exchange protocol which can be employed by a vehicle and corresponding RSU to converge on a mutually agreed secret key with the assistance of vehicle server. e presented SMEP-IoV scheme meets the security as well as performance requirements of IoV. To analyze the security on formal basis, 2 Security and Communication Networks the SMEP-IoV employed BAN logic. According to the demonstrated results, the lightweight SMEP-IoV achieves the desired security properties. e research article titled "Improved Secure and Lightweight Authentication Scheme for Next-Generation IoT Infrastructure" proposed a secure as well as lightweight authenticated key agreement technique for next-generation IoT infrastructure after reviewing and presenting the weaknesses in Rana et al. [24].
is study suffers from vulnerability to offline password guessing attack and privileged insider threats. e improved scheme solves the drawbacks of reviewed scheme, and its security features are proven under formal as well as informal analysis. ey proved the security properties of the scheme using BAN logic as well formal analysis based on the RoR model. Ultimately, they took a comparative analysis of the proposed work and previous related schemes and found that their scheme is not only efficient as far as computational and communicational costs are concerned but also robust regarding the security features. Moreover, the performance evaluation also acknowledges the effectiveness of proposed scheme in terms of time and memory consumption. e research article titled "AVoD: Advanced Verify-on-Demand for Efficient Authentication against DoS Attacks in V2X Communication" presented a technique for preventing Denial-of-Service (DoS) threats in the interaction of autonomous cooperative driving vehicles by employing security credential management system [25]. e contributed technique minimizes the authentication costs on the basis of classification for similar messages into several categories, while verifying the authenticity for the first message as characterizing the group. is scheme has been duly tested with experiments and demonstrations, while the scheme significantly enhances the speed of processing messages by reducing DoS attacks, attributing to the contributed scheme. e research article titled "V2X-Based Mobile Localization in 3D Wireless Sensor Network" presented a rangefree localization algorithm with respect to sensors in 3D wireless sensor network architecture on the basis of flying anchors [26]. e developed algorithm is quite suitable for localization of the vehicle as it employs the vehicle-to-infrastructure (V2I) based positioning algorithm. It chooses the multilayer C-shaped trajectory for random walk of the mobile anchor-based nodes which is installed with GPS. ese anchor nodes keep transmitting beacon signal besides the information of position towards unknown nodes to form a triangle using three further nodes upon receipt of RSSI values. ereafter, distance is calculated using link quality induction for every mobile anchor node using centroidbased formula for computing localization error. e results of simulation indicate that C-CURVE algorithm demonstrates higher efficiency even in multipath fading. e presented algorithm affords higher accuracy despite the presence of noise, due to the employment of recurring LQI values.
We would like to extend our profound appreciation to all the reviewers and authors for their timely and worthy contributions. Moreover, we would like to thank the Editorin-Chief of Security and Communication Networks, Hindawi, for granting us the privilege to contribute this special issue in the worthy journal. We hope this special issue will provide useful insight to the researchers seeking for the novel prospects to secure vehicular communications.

Conflicts of Interest
e guest editors declare that there are no conflicts of interest regarding the publication of this special issue.