Systematic Review of Scalable Blockchain-Based Digital Signature Frameworks for Healthcare Data Security

Abstract

This is the first PRISMA-guided systematic review of scalable blockchain digital signatures for healthcare, synthesizing evidence from 85 peer-reviewed studies published between 2015 and 2024. The review examines five thematic areas: digital signatures, consensus mechanisms, smart contracts, hybrid blockchain architectures, and regulatory compliance. Particular emphasis is placed on scalability challenges and the role of alternative consensus protocols, such as Proof-of-Stake and Delegated Proof-of-Authority (DPoA), in addressing the energy and latency limitations of Proof-of-Work (PoW). Findings highlight the value of smart contracts in automating consent and authentication processes, while hybrid blockchain models are shown to balance security with scalability. The synthesis also identifies persistent challenges, including interoperability with legacy systems, energy consumption, and compliance with GDPR and HIPAA regulations. Importantly, emerging approaches such as Layer-2 scaling, AI-enhanced validation, and post-quantum cryptography are highlighted as promising directions. By integrating technical and regulatory perspectives, this review contributes a critical roadmap for researchers, healthcare providers, and system architects seeking secure, efficient, and regulation-compliant blockchain frameworks