EHRShare: A Blockchain-Based Electronic Health Record Sharing System with Zero-Knowledge Proof

Abstract

This paper presents a secure and privacy-preserving framework for Electronic Health Record (EHR) sharing using blockchain and zero-knowledge proofs (ZKPs). The system enables patients to control access to their health data through smart contracts, ensuring that only verified users can access sensitive information. ZKPs authenticate users without revealing identities, preserving confidentiality. IPFS is used for off-chain storage, reducing on-chain costs and improving scalability. The proposed model supports dynamic access control, including permission granting, revocation, and automatic expiry. This approach enhances data integrity, verifiability, and privacy in decentralized healthcare environments.