## 5 Decentralization of VANETs
### Enhancing Robustness and Privacy-Preserving Data Sharing with DLT
#### 5.5.2 Advantages over Traditional Methods  
DLT removes single points of failure, makes data more accurate and reliable, and provides a safe and open space for exchanges. The advantages of DLT over traditional data management methods in VANETs are shown in Table 3. These studies focus on the advantages of DLT, such as better security, more accurate data, decentralized management, and quick approval of data.  
\begin{table}
\begin{tabular}{p{142.3 pt} p{227.6 pt}} \hline \hline
**Paper** & **Main Idea** \\ \hline FDC2022 [83] & The study investigates the incorporation of blockchain technology into digital twins in VANETs to improve intelligent transport in smart cities. The aim is to utilize blockchain for the safe transmission and storage of data. The simulation findings demonstrate that the created model guarantees robust network security and achieves low latency performance. This provides a solid experimental foundation for the advancement of intelligent and secure transportation in smart cities. \\ \hline PNC2022 [84] & Introduces a certificate management system for VANETs that utilizes blockchain technology. The goal of this method is to fix problems with renewing certificates and taking away vehicles. It makes privacy better by using pseudonym certificates and ring signatures for a voting-based annulment system. It aims to cut down on wait times in centralized management and improve the safety and efficiency of smart transport networks as a whole. \\ \hline SRI2022 [85] & Using blockchain technology, it shows a way to encrypt messages and handle data for VANETs. This aims to lower cyber risks by ensuring privacy, being impossible to deny, and being strong against attacks like 51\% attacks, eclipse attacks, and double-spending. The TB-SCDM system for authentication and authorization in VANETs is better than the current ways because it uses less storage space and computing power. \\ \hline LPT2021 [86] & Shows how to use blockchain technology to control the sharing of information in VANETs. A hybrid trust model is used to figure out how reliable shared material is, which is meant to ease security concerns. The system uses the PBFT consensus protocol, which checks to see how many times RSUs and cars are interacting to make sure they are exchanging information honestly and actively. There have been experiments conducted to show that these methods can be used in real life. \\ \hline ZWP2020 [87] & Gives a way to make sure that sending and receiving data is safe in VANETs, focusing on responsibility, privacy protection, and transmission privacy. The plan sets up the Fengyi system and adds a Trusted Ledger Model (TLM). The study shows that the TLM is a good way to make sure that VANETs can share data securely. \\ \hline DJW2020 [88] & The study used a hierarchical network that uses 5G and blockchain technologies to discuss how hard it is to keep data secure in VANETs. They used the PBFT algorithm to create a system for sharing data that emphasizes secure and quick data storage and transfer. To achieve this, they use the properties of data immutability and decentralization. \\ \hline \hline \end{tabular}
\end{table}
Table 3: A comparison of DLT and traditional data management in VANETs.