Privacy preserving cloud data security using blockchain-based public key infrastructure: A systematic review

Abstract

Cloud computing has become fundamental to modern digital services, with Public Key Infrastructure (PKI) serving as the primary mechanism for authentication, certificate management, and secure communication. However, conventional centralized PKI introduces challenges such as single points of failure, certificate revocation inefficiencies, limited scalability, compliance issues, and reduced trust, motivating the adoption of blockchain-enabled PKI. This PRISMA-guided Systematic Literature Review synthesizes evidence from 56 studies published between 2015 and 2025 to evaluate blockchain-enabled PKI frameworks for privacy-preserving cloud security. The review examines five major research domains: identity management, access control, data integrity, privacy-preserving cryptography, searchable encryption, and IoT/Fog/Edge integration. The synthesized evidence indicates that identity management, access control, and data integrity are the dominant research themes, with healthcare, cloud storage, and IoT/Fog computing as the primary application domains. Emerging directions include post-quantum PKI, cross-chain certificate management, AI-driven trust evaluation, and lightweight blockchain architectures. The review also identifies unresolved challenges, including scalability, computational overhead, certificate revocation, interoperability, and energy-efficient consensus mechanisms. Overall, this study provides an evidence-based synthesis of current research trends, highlights critical research gaps, and offers practical guidance for developing secure, scalable, and decentralized cloud trust infrastructures.