A lightweight scalable and dynamic blockchain-based model for storing and retrieving patient healthcare records

Recent studies have explored blockchain technology for healthcare data storage and retrieval, addressing challenges related to scalability, trustworthiness, timely access, and patient privacy preservation. This paper presents a lightweight, scalable, and dynamic blockchain-based model, termed DHC, designed for efficient storage and retrieval of patient healthcare records. The model introduces several data structures aimed at enhancing the scalability of the blockchain network while ensuring data integrity and scalability in an off-chain environment. Patient healthcare data are stored daily in distinct proposed local dynamic blocks, which are subsequently added to a new local dynamic chain at the respective healthcare facility. These local dynamic chains periodically announce their final blocks to the blockchain network, where they are aggregated into a proposed global block. This block is verified through a two-layer, lightweight, energy-aware consensus algorithm (TLC). After validation, the global block is incorporated into the global chain. Additionally, the proposed access-control mechanism facilitates timely data access while safeguarding patient privacy. Evaluations of DHC under various scenarios demonstrate improvements in time complexity and storage efficiency, as well as higher retrieval rates for patient records. Furthermore, the TLC consensus protocol helps mitigate DDoS, Sybil, Eclipse, and fork attacks.