# Self-Sovereign Identity-Based E-Portfolio Ecosystem
## 1 Introduction  
Since 2019, significant changes have unfolded in university admissions processes, pivoting from a predominant focus on entrance exam scores to a heightened consideration of a student's enduring academic performance. This shift has highlighted the limitations of conventional paper documents in the eyes of university reviewers. In response, the proposal of an e-portfolio system [1] has emerged as a solution, offering reviewers a more comprehensive understanding of a student's academic and extracurricular achievements. By embracing the e-portfolio system, reviewers gain access to a detailed breakdown of a student's final scores across various academic subjects, coupled with insights into their engagement in extracurricular activities. This comprehensive approach provides deeper insights into a student's passions and achievements, aiding reviewers in making informed decisions. Significantly, the e-portfolio system has taken the place of conventional paper records, leading to a more streamlined admissions process, greatly enhancing overall efficiency. The traditional e-portfolio system encounters several challenges. First, students find it cumbersome to manage multiple text-based password authentication systems, as high schools and activity organizations are often reluctant to adopt social logins like Google or Facebook. This reliance on text-based passwords hinders the creation of a unified digital identity. Additionally, the lack of a trusted connection between institutions and reviewers disrupts direct data sharing, leading to admissions delays that can negatively affect acceptance rates. The absence of a robust authentication method also raises concerns about the reliability of submitted data, making it difficult for reviewers to quickly verify the accuracy and authenticity of information due to limited review time. This can result in inaccuracies in admissions decisions, disadvantaging deserving students. Moreover, students may require greater control over who can access their data. By implementing a decentralized identity management system, students can selectively share their learning history, allowing them to avoid disclosing unfavorable academic records orincomplete assessments. Consequently, there is a pressing need for a system that ensures the credibility and authenticity of student data. Such a system would streamline authentication, facilitate direct data sharing, and provide reviewers with accurate information, ultimately enhancing the admissions process for all stakeholders. To address the issues discussed earlier, we propose a solution based on a self-sovereign identity-based personal information security control infrastructure for the e-portfolio ecosystem, using blockchain technology. This infrastructure consists of two parts:  
Decentralized identity blockchain: The decentralized identity blockchain enables users to have a self-sovereign identity, allowing them to fully control their own identity without relying on centralized services. Application blockchain: A blockchain specifically designed for the e-portfolio scenario enables students to share their documents, allows institutions to authorize awards, helps teachers upload student e-portfolio documents, and provides university reviewers with access to review students' documents. Using blockchain and smart contracts, users can log in with a digital signature, eliminating the need for passwords, which are often vulnerable to hacking or lost. The e-portfolio application blockchain allows individuals to grant their consent and provide their information to reviewers, while also enabling trusted educational bodies to audit the information provided by activity groups. Access to any student data is permitted only with the student's explicit authorization, ensuring that the data's credibility and authenticity are maintained. This provides reviewers with reliable information to make informed decisions.