## 5 Simulation Result Analysis  
The CSSoB technology entails the separation of sensitive and insensitive data during the storage process based on the user's preferences. The sensitive data are first divided into blocks, encrypted, and then stored in memory. Simultaneously, metadata are acquired. In contrast, insensitive data are directly separated into blocks and stored in memory, and metadata are also obtained. The metadata contain the block information of the data, which are then encrypted and stored in the blockchain. When retrieving data, the user accesses the block data by referring to the metadata information recorded in the blockchain. The data are then reconstructed to obtain the original data [16]. Compared with the literature [12], this scheme adopts the storage method of IPFS, which has the advantages of permanent storage of data, fast download of data, and security, and is not easy to be attacked. At the same time, the decentralized blockchain technology is adopted to make the data more secure and convenient to share. In the literature [13], the RSA encryption algorithm is adopted, while in this paper, the ECC algorithm is adopted, which has fast operation speed, low resource consumption, and the same encryption strength as the RSA algorithm, which can be achieved by using a shorter key. As shown in Table 1, the performance of the ECC and RSA encryption algorithms is analyzed. It can be seen that in addition to low maturity, ECC has excellent performance in other aspects. Therefore, this paper adopts ECC to encrypt the data and ensure the safe storage of the data. As shown in Table 2, the experimental hardware server of this system is Aliyun, with an 8-core CPU configuration, 16.00 GB memory, 2 TB hard disk size, and 500 Mbps LAN speed. As illustrated in Figure 9, the storage rate of CSSoB decreases gradually as the proportion of sensitive data increases. This can be attributed to the fact that CSSoB requires encryption of sensitive data, and as the number of sensitive data increases, the encryption time increases, thereby causing a decline in the overall system rate. Accordingly, it can be deduced that the proportion of sensitive data in the big data environment poses a chal \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Name** & **Ripeness** & **Security (Depends on Key Length)** & **Operational Speed** & **Resource Consumption** \\ \hline RSA & High & Low & Slow & High \\ ECC & Low & High & Fast & Low \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of the ECC and RSA algorithms. \begin{table}
\begin{tabular}{c c} \hline \hline
**Name** & **Data** \\ \hline CPU & 8 core CPU \\ Memory & 16.00 GB \\ Hard disk & 2 TB \\ LAN speed & 500 Mbps \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Experimental hardware parameters. lenge to the system's read and write performance, and thus, users must judiciously adopt different storage systems to manage their data according to their specific requirements. Figures 10 and 11 present a comparison of the read and write performance of the CSSoB scheme in the local and LAN settings. The test results show that whether it is a local or local area network, when the file is less than 40 MB, because the read and write rate is a linear rise, once the file is greater than 40 MB, the read and write rate will maintain a constant trend. This is because when the file is too small, the proportion of some initialization and network connection time increases greatly, resulting in a linear rise, and when the file is too large, the proportion decreases, and the processing data are more stable. The test also shows that the read/write rate of the CSSoB on the local is higher than that on the LAN. This is because the read/write rate of the CSSoB on the local is not affected by the network speed. The reason for the decrease in test reading in Figure 10 is that when the file size is large, the server needs to read the hard disk several times, which slows down the rate and thus decreases. Figure 10: CSSoB performance local test.