Blockchain-Based Digital Identity Management: A Comprehensive Review of Security, Privacy, Regulatory Perspectives, and Future Directions

Abstract

Secure and reliable digital identity management has become a cornerstone of online transactions and e-government services. Traditional centralized identity systems suffer from vulnerabilities such as single points of failure, data breaches, and limited user control. Blockchain offers a decentralized, tamper-resistant framework enabling self-sovereign identity (SSI), decentralized identifiers (DIDs), and verifiable credentials (VCs).This paper systematically reviews 72 peer-reviewed studies and official standards published between 2016 and 2024, following the PRISMA framework. The included papers were distributed across major publication years, with quality assessment ensuring methodological rigor. Comparative analysis and case studies—including Estonia’s e-Residency, ID2020, Civic, ShoCard, and recent Asian and African initiatives—illustrate global adoption differences in security, privacy, scalability, and interoperability. Beyond immutability and privacy, this study highlights emerging vulnerabilities such as Sybil attacks, quantum threats, and side-channel risks, while also emphasizing AI-driven verification advances. Descriptive statistics and trend visualization support quantitative insight into identity model evolution. The findings recommend hybrid blockchain architectures and regulatory sandboxes as practical pathways for balancing decentralization, compliance, and social inclusion.