A Scalable and Privacy-Preserving Hybrid Blockchain Architecture for Secure Healthcare Data Management

Abstract

The protection of sensitive medical information has become a critical concern in modern digital healthcare. This study introduces a Hybrid Architecture that ensures secure and reliable healthcare data management through the integration of blockchain technology with off-chain and on-chain mechanisms. Patient records are encrypted using AES-256-GCM, stored in the InterPlanetary File System (IPFS), and verified using Merkle Tree structures, with only the root values anchored on Ethereum smart contracts. This design guarantees data security and integrity while achieving significant gas optimization by reducing on-chain storage costs. Experimental evaluation demonstrates that the proposed system achieves high scalability, efficient transaction processing, and strong resistance to tampering, ensuring confiden tiality and auditability. By combining blockchain, cryptographic techniques, and distributed storage, the framework addresses pressing challenges of security, privacy, and trust in healthcare ecosystems. The results highlight the potential of Hybrid Archi tecture models to deliver a cost-effective, privacy-preserving, and scalable solution for next-generation Healthcare Data Security.