# Delegation-Based Personal Data Processing Request
## 2 Background and Related Work
### Related Works of Blockchain-Based GDPR  
Features of BC such as integrity, transparency, reliability, and traceability are effective when they are applied to tasks that require compliance management. To manage personal data or GDPR compliance, many researchers have performed research based on BC [8; 15; 28; 29; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42]. For related research analysis, by the SLR (Systematic Literature Review) approach, we selected research questions and derived key search terms such as 'Personal Data', 'Blockchain', 'GDPR', and 'Notarization' from the research questions, and we used them to search and collect papers. However, many of the extracted papers provide only preliminary methodological investigations. Through the primary analysis of the collected papers, we classified the papers with solution implementation plans or implementation examples and performed secondary intensive analysis. Table 1 shows related studies that suggest blockchain-based unique technologies in relation to GDPR compliance. As a result of analyzing the related studies, the main research areas of the related studies are shown in Table 2. \begin{table}
\begin{tabular}{l c c} \hline \hline
**No** & **Research Works** & **Proposed Technology** \\ \hline R01 & [PERSON] et al. in [29] & BC-based data provenance architecture in cloud environment with privacy \\ R02 & [PERSON] et al. in [30] & Protecting privacy and self-sovereignty through blockchains for OpenPDS \\ R03 & [PERSON] et al. in [31] & BC as a notarization service for data sharing with personal data store \\ R04 & [PERSON] et al. in [32] & GDPR legislative compliance assessment \\ R05 & [PERSON] et al. in [33] & BC-based personal data management \\ R06 & [PERSON] et al. in [34] & GDPR-compliant personal data management \\ R07 & [PERSON] in [35] & BC-based consent manager for GDPR compliance \\ R08 & [PERSON] et al. in [36] & BC identity management system to secure personal data sharing in a network \\ R09 & [PERSON] et al. in [37] & Consent management platform for personal data processing using BC \\ R10 & [PERSON] et al. in [38] & BC-based personal data and identity management system \\ R11 & [PERSON] in [39] & Privacy by design platform for GDPR compliance \\ R12 & [PERSON] and [PERSON] in [40] & Automating GDPR compliance using policy integrated BC \\ R13 & [PERSON] in [41] & Protection and control of personal identifiable information \\ R14 & [PERSON] et al. in [42] & BC-based platform for GDPR-compliant personal data management \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Overview of related works based on BC. As a result of analyzing works related to BC-based personal data protection and GDPR compliance management, it can be seen that various methods and solutions are being studied for the expansion of GDPR compliance by using the characteristics of the BC such as integrity, confidentiality, transparency, and audit traceability. However, most of the works that tried to solve the privacy problem using BC do not consider GDPR, so it is difficult to apply it as a method to meet the requirements according to each regulation of GDPR. On the other hand, most of the works that suggested the application of BC to meet the requirements of the GDPR only present a conceptual design and did not present a practical implementation method of BC. Even works that presented practical implementation methods did not suggest a method to address the risk that BC-based systems may themselves violate GDPR principles because of their BC nature or how the records stored in BC could be utilized by an outer auditor for compliance audits. Most of the works designed the system structure under the premise that SP stores and manages personal data. So, the proposed architecture is designed so that users go through the system of SP to access BC. Nevertheless, the issue of the objective reliability of the data stored in BC was not taken into account.