# Blockchain-Based Quality Assurance System for Academic Programs
## 4 Experimental Results and Discussion
### Time Consumption of Cryptographic Operations  
The experiments conducted in this research implemented three cryptographic schemes. This aims to provide the required security services to protect sensitive quality information produced by the QAS. In particular, the experiments implemented the ECCDSA and RSADSA to provide digital signatures. After the quality files were digitally signed, they were encrypted using the AES algorithm to preserve the confidentiality of the content. Additionally, the current study investigated the implementation of the ECIES scheme to provide both authentication and confidentiality. Table 3 presents the time consumption in milliseconds of various cryptographic operations for the three schemes. The cryptographic schemes were tested on various standard quality reports of variable sizes. It can be noticed that the ECCDSA takes less time compared to the RSADSA. This is expected because of the ability of the ECC to provide the required level of security using much smaller key sizes. Therefore, the current research adopts the ECCDSA as the standard algorithm to provide non-repudiation and authentication services. In addition, the AES algorithm was implemented to provide confidentiality. The experimental results showed that the ECIES algorithm takes a longer time compared to other algorithms. This is perhaps due to the need to exchange keys and generate an HMAC. The algorithm does not provide a non-repudiation service, which is required for many quality transactions. Therefore, it is not recommended for the current quality system implementation.  
Figure 10 shows a comparison in terms of the total time consumed by the digital signature and encryption operations of the ECCDSA and RSADSA and the total time consumed by ECIES operations. It can be noticed that the ECCDSA achieved the best results, followed by the RSA. However, the ECIES algorithm took a longer time to execute in comparison to other cryptographic schemes.  
Table 4 presents the time consumption (in seconds) results for different cryptographic operations with blockchain transactions for data sizes ranging from 400 to 1200 KB. It is evident that the AES_ECCDSA hybrid cryptographic scheme consistently performs the best compared to other schemes. This is expected, as the time consumption of blockchain transactions is directly related to the file size, regardless of the cryptographic algorithm used. The lowest time consumption was observed when using the AES_ECCDSA for encrypting, signing, and storing a file of approximately 400 KB. In contrast, the ECIES scheme resulted in the longest processing time for files compared to other algorithms.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Quality Reports**} & \multirow{2}{*}{\begin{tabular}{c} **Size** \\ **(Kilobytes)** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **Time Consumption of** \\ **AES\_ECCDSA** \\ **Cryptographic Operations** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **Time Consumption of** \\ **AES\_RSADSA** \\ **Cryptographic Operations** \\ \end{tabular} } & \multicolumn{2}{c}{\
\begin{tabular}{c} **Time Consumption of** \\ **ECIES Cryptographic** \\ **Operations** \\ \end{tabular} } \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Quality Contracts \\ Course Reports \\ Annual Program Specification \\ Program Specification \\ \end{tabular} } & 447 KB & 3 & 33 & 2 & 40 & 150 \\  & 1215 KB & 43 & 64 & 43 & 81 & 282 \\  & 8088 KB & **57** & 131 & **57** & 174 & 739 \\  & 597 KB & 14 & 54 & 14 & 69 & 218 \\  & 1167 KB & 18 & 58 & 18 & 86 & 227 \\ \hline \end{tabular}
\end{table}
Table 3: Time consumption results for the cryptographic operations.  
The following discussion highlights the advantages of utilizing the proposed blockchain-based ecosystem from a security perspective.