## 2 Security and Privacy Requirements of VANETs and Potential Enhancements  
The existing solutions that offer essential requirements for VANETs, such as confidentiality, integrity, minimal trust assumptions, privacy preservation, and scalability, are notably scarce and present significant challenges. Following an extensive review, we identified several obstacles that are commonly encountered across all VANET architectures, which are detailed and presented in Table 1. The table summarizes the crucial security and privacy requirements that are necessary for the strong operation of VANETs. It also provides a thorough examination of the various security aspects, emphasizing important areas such as Authentication, which employs cryptographic methods like digital signatures and certificates to verify identities within VANETs; Integrity, which guarantees secure data transmission through cryptographic hashes and digital signatures; and Availability, which concentrates on network resilience against threats such as Denial of Service (DoS) attacks. It also emphasizes the utmost significance of Nonrepudiation for ensuring legal responsibility, Privacy for protecting user identity credentials, and Access Control for regulating information flow and network resources. Table 1 discusses the security and privacy requirements of VANETs.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Requirement** & **Description** \\ \hline \multirow{3}{*}{Authentication} & Authentication in VANETs uses cryptographic techniques like digital signatures and certificates to verify the identity of communicating vehicles and infrastructure, preventing impersonation and false data dissemination. \\ \hline \multirow{3}{*}{Integrity} & Integrity in VANETs ensures data transmission between vehicles and infrastructure is secure, using cryptographic hashes and digital signatures for safety-critical messages like collision warnings, and Message Authentication Codes (MACs) for verification. \\ \hline \multirow{3}{*}{Availability} & VANETs’ availability, including resilience against DoS attacks, is crucial for emergency and safety communication. Redundant system designs and efficient network management strategies enhance availability. \\ \hline \multirow{3}{*}{Nonrepudiation} & Nonrepudiation in VANETs ensures message transmission, preventing entities from denying origin, crucial for legal scenarios like traffic violations and accident investigations, using digital signatures. \\ \hline \multirow{3}{*}{Privacy} & VANETs protect user identities and locations, using pseudonyms and cryptographic techniques to prevent tracking and profiling while balancing anonymity with security needs for accountability. \\ \hline \multirow{3}{*}{Access Control} & Access Control in VANETs manages sensitive information flow and efficient communication. It can be achieved through role-based systems or cryptographic techniques, preventing unauthorized use of network resources. \\ \hline \multirow{3}{*}{Efficiency} & VANETs require efficient security mechanisms, cryptographic algorithms, and streamlined protocol designs to ensure rapid communication in high-speed vehicles while balancing security with fast data exchange. \\ \cline{1-1}  & \\ \cline{1-1}  & \\ \cline{1-1}  & \\ \cline{1-1}  & \\ \end{tabular}
\end{table}
Table 1: Security and privacy requirements of VANETs.  
This research paper aims to emphasize trust management through decentralization using a public, transparent, and immutable ledger on a peer-to-peer network. This study also seeks to leverage the transparency and data immutability of VANETs to advance the field.