## 4 Experiments and Results: Performance Analysis
### Simulation Results
Furthermore, Figure 16 depicts the maximum and median verification latencies in the event of a security breach, as well as how the current and proposed methodology can provide secure communication in the event of such an attack. Figure 18: Impact of node mobility on maximal verification. The existing process used multiple security measures at several levels of interaction, thereby making it vulnerable to brute force attacks. However, the proposed system uses a blockchain across the entire network, thus making it challenging to anticipate or compromise the hashed data of all nodes (vehicles) at once. Figure 15 depicts the probability situations of an authentication method, where, as the density of MNs (such as compromised vehicles or peer stations) increases, both techniques can still identify the valid nodes. The suggested system, which maintains a blockchain ledger for each node, can determine the trusted node. The accuracy ended up being close to 86%, which will improve over time as detected MNs are removed from the system. The identification and isolation of MNs based on trust did not impair the functioning of the rest of the network. After a certain period, the proposed mechanism evaluates the trust and ratings of other nodes in the network. Nodes that have been attacked and are acting maliciously will receive a poor grade and trust due to high packet-drop rates, wormholes, and falsification attacks, and they may eventually be isolated from the network. In our effort to rigorously evaluate the proposed technologies, we conducted some extra experiments. The objective was to compare our proposed method's performance against traditional VANET security solutions across multiple key metrics. The metrics selected for this comparison included the detection rate, latency, transmission efficiency, scalability, and fault tolerance. These metrics were chosen due to their critical importance in the assessment of VANET architectures. We utilized a simulation environment developed using Python, with ns-3 simulations providing the backbone for our experimental setup. This approach allowed for a comprehensive analysis of both the traditional and dual-layer blockchain architectures under various network conditions. The results, as depicted in the accompanying bar graph (see Figure 20), demonstrate a marked improvement in performance when employing the proposed mechanism:  
Detection Rate: The proposed technology exhibited a detection rate of 86%, which is a significant improvement over the traditional architecture's 75% detection rate. This increase can be attributed to the enhanced security protocols and decentralized nature of the blockchain, which aid in more effective anomaly detection. Latency: In terms of latency, the blockchain-based solution showed a reduction, thereby indicating more efficient data processing and transmission capability. This reduction is crucial in VANET environments where real-time data transmission is paramount. Figure 19: Evolution of network efficiency and trust rating over time. Transmission Efficiency and Scalability: The transmission efficiency and scalability of the proposed system were also notably higher. These improvements are likely due to the distributed nature of blockchain technology, which allows for more efficient data handling and better accommodation of increasing network sizes. Fault Tolerance: Finally, the fault tolerance of the proposed approach was observed to be superior. This is consistent with the inherent resilience of blockchain systems against points of failure and network attacks. Figure 21 corroborates the efficacy of the proposed blockchain-based approach in enhancing security and reliability in VANETs. By effectively mitigating the risks associated with collusion and false information injection, the architecture ensures a secure and trustworthy vehicular communication network. The comparative analysis underscores the substantial advantages of the dual-layer blockchain architecture over traditional VANET security solutions.