MedBlock: Privacy-Preserving Framework for Next-Generation Electronic Health Records

Healthcare organizations face significant challenges in securely managing and exchanging sensitive patient data across diverse systems. Electronic health records (EHRs) face pressing security and privacy challenges due to centralization, fragmented systems, and inadequate access controls. This research presents MedBlock—a decentralized blockchain framework to transform EHR management. MedBlock employs a permissioned blockchain fabric and hybrid on-chain/off-chain storage to balance transparency with confidentiality. Metadata, hashes, and pointers maintain an immutable record on-chain while bulk medical data resides encrypted off-chain. Smart contracts encode granular access policies aligned with patient consent. Integration gateways connect the blockchain protocols with existing EHRs and insurer systems to avoid workflow disruption. A prototype implemented on Hyperledger Fabric was evaluated under simulated transaction workloads. Results demonstrated MedBlock’s ability to achieve over 14,000 transactions per second throughput with sub-second latency while preventing unauthorized data access. Core technical components include consortium consensus, encrypted storage, and compliance rules incorporated at the protocol level. MedBlock advances blockchain techniques to overcome systemic EHR limitations around security, privacy, interoperability, and patient control. The decentralized architecture transforms outdated centralized databases into an integrated, resilient record management platform centered on data sovereignty. The technical foundations developed in this research pioneer next-generation health information exchange ecosystems.