# Reliable Integrity Preservation Analysis of Video Contents with Support of Blockchain Systems
## 4 Evaluation
### Hardware and Blockchain Platform Dependency  
The execution time of the proposed scheme depends on both the hardware specification of the front-end server and the platform of the back-end blockchain system. To check the effect of hardware specification of the front-end server, we replace the notebook with a low-performance IoT device, Raspberry Pi 3 with 1.2 GHz Quad Core and 1 Gbytes memory [33; 34]. In the Raspberry Pi 3, the execution time of analyzing integrity is similar to that in Table 3. The operation required for analyzing integrity in the front-end servers is to just extract the file header fields, and thus it is rarely affected by the hardware performance of the front-end server. The execution time of comparing video frames in the Raspberry Pi 3 is increased by about 48%, compared to that in Table 3. This operation is heavily affected by the hardware performance of the front-end server. The execution times of comparing video frames and searching for the result in the Raspberry Pi 3 are similar to those in Table 3. These operations are rarely affected by the hardware performance of the front-end server, but are heavily affected by the platform performance of the blockchain system. Next, we replace the blockchain platform with other public blockchain platforms such as Ethereum [27] and Tron [35] in order to check the effect of the blockchain platform. We use their non-commercial test networks instead of their commercial main networks: Ropsten network for Ethereum platform and Shasta network for Tron platform. We do not consider the private blockchain platform such as Hyperledger Fabric [36] and Quorum [37], because the hardware and network specifications of private blockchain platforms are not fixed or determined by the private platform operator. The private blockchain platform may be not suitable for the proposed scheme because the disclosure of smart contracts and stored data in the blockchain system requires the permission of the network operator in the private platform. In the Ethereum platform, the execution times of analyzing integrity and comparing videos are similar to those in Table 3. The execution time of the searching result is increased by about 740% compared to that in Table 3, and the operation to store results \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Range of Video** & **Analyzing** & **Comparing** & **Storing** & **Searching** \\
**File Size (Mbytes)** & **Integrity** & **Videos** & **Result** & **Result** \\ \hline
10\(\sim\)50 & 212 ms & 19,233 ms & 1744 ms & 637 ms \\
50\(\sim\)100 & 218 ms & 38,568 ms & 2824 ms & 938 ms \\
100\(\sim\)200 & 221 ms & 71,201 ms & 3424 ms & 1180 ms \\
200\(\sim\)500 & 223 ms & 136,119 ms & 4026 ms & 1315 ms \\
500\(\sim\)1024 & 226 ms & 293,744 ms & 5725 ms & 1974 ms \\
1024\(\sim\)1536 & 233 ms & 586,983 ms & 7332 ms & 2876 ms \\
1536\(\sim\)2048 & 234 ms & 722,726 ms & 9154 ms & 3527 ms \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Execution time against video size on the blockchain system. takes about 650 s. In the Tron platform, the execution times of analyzing integrity and comparing videos and searching result are also similar to those in Table 3. The execution times for storing the result and searching for the result are decreased by about 32% and 16%, respectively, compared to that in Table 3. Through these experiments, it is confirmed that the execution speed of comparing video frames depends on the hardware performance of the front server, and the execution speeds of the storing result and the searching result depend on the platform performance of the public blockchain system. The proposed scheme is applicable to any public blockchain platform supporting two basic functions: storing data permanently and searching for the stored data. When the proposed scheme employs other public blockchain platforms instead of Klaytn, Ethereum and Tron, the metrics of storing time, searching time and the required blockchain operation fee are changed according to the employed blockchain platform.