## 1 Introduction  
Intelligent transport systems depend on Vehicular Ad hoc Networks (VANETs) for dynamic vehicle-roadside infrastructure communication. VANETs improve road safety and efficiency by providing wireless connectivity for traffic control and autonomous driving. The growing complexity and requirement for real-time data processing in these networks require comprehensive security and privacy procedures to ensure vehicular communication system stability and trustworthiness. However, this brings up a series of significant challenges, such as the concepts of trust, privacy, and scalability. To ensure the sustainability and reliability of these systems, it is crucial to address these challenges [1; 2; 3]. To ensure effective functionality and enhance safety, it is essential to provide better trust in VANETs. VANETs use Certificate Authorities (CAs) to authenticate automobilesand roadside equipment. Building trust in VANETs is very important because it is what makes safety-critical applications like avoiding collisions, managing traffic flow, and planning routes dynamically possible [4; 5; 6] work. However, relying on centralized CAs has significant concerns. For example, a CA may issue a certificate of trustworthiness that can be compromised in the event of a successful attack. This has the potential to allow adversaries to impersonate authentic entities, leading to the dissemination of inaccurate information or even more concerning, providing attackers with the capability to alter traffic patterns. The existence of these vulnerabilities has the potential to significantly disrupt vehicle communications, leading to serious safety consequences such as crashes or extensive traffic congestion. Ensuring the mitigation of this risk is critical for the ongoing development of VANETs. The CertLedger architecture [7] improves the existing weaknesses of PKI architecture using validity, storage, and revocation procedures of TLS certificates, simplifying the management of Trusted CA certificates within a unified and immutable decentralized network such as Ethereum. During the process of TLS handshakes, clients acquire verifications of certificate validity directly from the owners of the domain, hence improving the privacy of users. The issue of privacy in VANETs is of similar significance, as vehicles consistently transmit confidential data [8; 9; 10]. The existing privacy safeguards, such as pseudonymization, may not be sufficient in the continuously changing landscape of VANETs [11; 12]. Therefore, there is a need for more sophisticated privacy-preserving methods. Unfortunately, the use of conventional PKI systems makes the system more expensive because the use of the same certificates would break the unlinkability requirement. Furthermore, the authors in [2] proposed the utilization of self-blindable certificates to enable anonymous communications, ensuring that the contact remains untraceable using a single valid certificate. Furthermore, the examination of data is of utmost significance. However, the attention should shift towards privacy issues. Hence, the incorporation of Privacy Enhancing Technologies (PETs), including homomorphic encryption [13], multiparty computation [14; 15; 16; 17], private set intersection [18], and trusted execution environments, such as HSM and SGX [1], is crucial in VANETs. This connection allows for complete analysis that can assist manufacturers and road workers in building new roads or improving existing ones, based on informed data-driven choices. The issue of scalability is also of greatest significance in the context of VANETs, especially considering the increasing connectivity and autonomy of vehicles in the ecosystem. As society enters a new era, the increasing quantity of vehicles on the road that have communication capabilities possesses the potential to surpass the current infrastructure's capacity to effectively handle and analyze the extensive volumes of data that are generated [19; 20; 21].