# Self-Sovereign Identity-Based E-Portfolio Ecosystem
## 6 Experimental Evaluation
### System Comparison  
In this section, we will conduct a comparative analysis with several research studies that share a common research interest. The outcomes of this comparison are presented in Table 9 for reference and evaluation. We employ six evaluation metrics to assess various schemes: access control model, data authorization, extracurricular activities, decentralized identity, parallel execution, and off-chain storage. The access control model elucidates data utilization methods. Data authorization reflects data trustworthiness. Extracurricular activities pertain to the system's capacity to record additional activities. Decentralized identity evaluates system security. Parallel execution addresses the system's ability to manage concurrent instructions, crucial for accommodating multiple users simultaneously. Lastly, off-chain storage enhances system efficiency by preventing prolonged execution times that may result from storing large data solely on-chain, necessitating a balance between on-chain and off-chain data storage. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Method** & **Function** & **Number** & **Average Latency (ms)** \\ \hline Offline sign & updatePermission & 1000 & 607.85 \\ Escrow private key & updatePermission & 1000 & 625.76 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Latency of offline signing vs escrow private key. Figure 27: Throughput and latency. Stuchain [40] is an innovative system that integrates two access control models, ABAC and RBAC, under the implementation framework of HLF. Within the Stuchain platform, teachers possess the capability to meticulously record and manage students' learning histories. Conversely, students have the authority to selectively grant access to their data to specific educational institutions that demonstrate an interest in their academic progress. It is important to highlight that students' learning histories are securely stored within a traditional database infrastructure, as opposed to being stored on a blockchain. Furthermore, given that these data originate from teachers, they may not encompass a comprehensive overview of all facets of students' interests. Consequently, educational institutions may not gain a complete understanding of each student's individual interests solely through these data. In a paper [41], authors proposed an e-portfolio system that was implemented using HLF. The e-portfolio system employs seven chaincodes: CPEM_C manages teacher evaluations and student targets for department administrators. VAAMC_C handles visitor access and file update authorizations. AUMSEAC_C oversees student e-portfolio updates, while CMSEAE_C is dedicated to course management system evaluations. IMTCTP_C manages course teaching process data, ERM_C handles student evaluation results, and IMSCPP_C deals with student course participation information. While this system effectively enables students to manage access control rights for their data and allows teachers to evaluate student learning history, it does have limitations. Notably, it does not provide a mechanism for recording extracurricular activities. This limitation could potentially hinder reviewers' ability to gain a comprehensive understanding of a student's overall development and capabilities. [PERSON] et al. [42] proposed a system that operates on the Ethereum blockchain and is structured around four layers, with a central secure e-portfolio management layer designed to provide dependable and secure management functionalities. These functionalities encompass activities such as the following: managing membership enrollments, user profiles, role assignments, and decentralized enrollment procedures; efficiently managing the issuance and r evocation of membership credentials; overseeing personal information within user profiles; and effectively administering user role assignments.