## 5 Evaluation
### Performance Analysis
Notably, both density structures exhibit shorter elapsed times compared to the use of K-Means and the native Gossip protocol. However, the propagation loss probability clearly demonstrates the superiority of the DC-SoC model under DC-SoC-DB dominance. In Figure 5(b), it is evident that OPTICS exhibits a certain level of incomplete propagation rate in dynamic networks, roughly comparable to the level observed with K-Means. In contrast, DC-SoC-DB demonstrates an incomplete propagation rate of only 0.3% in the worst case, resulting in a significantly lesser negative impact on the network's normal operation compared to other algorithms. Figure 5: Performance comparison of the static network. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Number of** & **Latency Range** & **Number of New** & **Number of** & **Number of** \\
**Peers** & & **Peers** & **Inactive Peers** & **Blocks** \\ \hline
100 & 1–30 ms & 15 & 10 & 10 \\
150 & 1–45 ms & 20 & 15 & 10 \\
200 & 1–57 ms & 35 & 20 & 10 \\
250 & 1–75 ms & 30 & 25 & 10 \\
300 & 1–95 ms & 35 & 30 & 10 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Parameters setup of network scale expanding. Table 4 displays the remaining parameter settings for each group of performance tests conducted in the dynamic network. The test results under continuous changes in network size are depicted in Figure 7. The change in network size encompasses variations in both the number of peers and the distribution range of peers, with the distribution range referring to the range of propagation delay between peers. Figure 7a demonstrates that as the number of peers in the network increases, the variation in peer propagation elapsed time is considerably more stable under the density clustering structure compared to other structures, resulting in significantly lower elapsed times. Notably, DC-SoC-DB shows a clear advantage, particularly when the number of peers exceeds 300. The significant change observed in K-Means can be attributed to its implementation of secondary clustering within clusters to accommodate the larger number of peers in the network. Figure 7b highlights the propagation reliability of the DC-SoC model in large-scale networks. The incomplete propagation rate remains consistently near zero, demonstrating that DC-SoC maintains a high level of reliability, regardless of network size. The specific settings for the required parameters in this set of experiments are provided in detail in Table 3. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Number of Blocks** & **Number of Newly Joined Peers** & **Number of Inactive Peers** \\ \hline
10 & 15 & 10 \\
20 & 20 & 15 \\
30 & 25 & 20 \\
40 & 30 & 25 \\
50 & 35 & 30 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Parameter setup for a dynamic network. Figure 6: Performance comparison of the dynamic network. Figure 7: Performance comparison of network scale changing. However, the assessment of data propagation reliability in a network cannot solely rely on the incomplete propagation rate. Given that the blockchain consists of numerous genuine user peers, the presence of malicious attackers in real-world applications is highly probable. To validate the robustness of the DC-SoC model against sophisticated attacks such as Sybil and Byzantine behavior, we conducted a series of experiments simulating environments with varying proportions of malicious nodes. A distortion transaction refers to a scenario where a peer accepts a false message from a malicious peer. Subsequently, upon successful propagation of the distorted message, the malicious peers collaborate to exploit the inconsistency in the ledger content and block sequence, thereby compromising the system's security. To enhance the complexity of the broadcasting environment and obtain objective test results, this set of experiments involves 300 peers in a dynamic network, utilizing the DC-SoC-DB clustering algorithm. Regarding the determination of the number of malicious peers, this paper adopts the experimental setup of malicious user detection researcher [PERSON] et al.