The electronic Know Your Customer (eKYC) identifies clients for organizations that maintain privacy and security. It automates the process and reduces the costs associated with manual KYC processes such as paper handling, physical storage, and manpower. A systematic review of identification systems is essential to provide a comprehensive overview of existing research to identify scope and gaps. This systematic literature review (SLR) using the PRISMA model investigates the revolutionary potential of blockchain technology, Decentralized Identifiers (DID), Self-Sovereign Identity (SSI), and selective disclosure in the context of eKYC and their combined effects. The evaluation is conducted to provide a thorough summary of the present state of blockchain-enabled eKYC by analyzing 44 selected research works from the 367 preliminary selections of research works from search results. The study explores how SSI and DID can improve user-centricity in identity verification. The review examines the theoretical foundations, empirical case studies, and practical implementations to elucidate the benefits, challenges, and emerging applications of this innovative convergence. This study explores that most of the identity management solutions are proposed on Ethereum (33%), and the second most used platform is Hyperledger(18%). About 51% of solutions used smart contracts. Banking (23%) and financial industries (19%) are the primary adopters of identity solutions. This study also analyzes the recommended solutions to these issues and addresses especially the privacy and security issues. A crucial finding of this review is that, still, there is no standard of eKYC, and it badly needs to be standardized for mass adoption.