A Systematic Review on Blockchain-Enabled eKYC: Leveraging SSI and DID for Secure and Efficient Identity Verification

The rapid evolution of digital identity verification demands solutions that balance security, privacy, and efficiency. The electronic Know Your Customer (eKYC) is a technological integration for client identification. It automates the process, reducing costs related to traditional KYC. This includes eliminating paper-based document management, reducing manpower needs, and minimizing human errors. This systematic literature review (SLR) uses the PRISMA model to investigate the revolutionary potential of blockchain-based eKYC, focusing on Self-Sovereign Identity (SSI) and Decentralized Identifiers (DID). The evaluation summarizes the current state by critically assessing 44 selected research works from an initial pool of 367. Our findings show that decentralized eKYC improves security with tamper-proof credentials and cryptographic verification. SSI and DID give users control over their data and selective disclosure. However, there are key limitations: (i) a focus on financial applications, ignoring IoT integration; (ii) a lack of comprehensive technical analysis on scalability and interoperability; and (iii) limited real-world case studies on regulatory compliance and challenges. This work combines insights from research and industry, highlighting the need for regulatory collaboration, hybrid architectures for scalability, and user-centric design. In addition, most identity management solutions are based on Ethereum (33%), followed by Hyperledger (18%). Around 51% of solutions use smart contracts, with banking (23%) and the financial industries (19%) being the primary adopters. It emphasizes the importance of standardized eKYC protocols, technical evaluations, and interdisciplinary collaboration for practical adoption across sectors.