MedExChain: Enabling Secure and Efficient PHR Sharing Across Heterogeneous Blockchains

2025-08-15

IEEE Internet of Things Journal

AI Summary

This work addresses the challenge of securely and efficiently sharing personal health records (PHRs) across heterogeneous blockchains in resource-constrained Internet of Medical Things (IoMT) environments. To this end, the authors propose MedExChain, a lightweight cross-chain framework that integrates a cross-chain communication protocol, a cryptographic reverse firewall (CRF), and a blockchain-based auditing mechanism. The design is formally verified using BAN logic and the Scyther tool to ensure resilience against both internal and external security threats. Experimental results demonstrate that MedExChain achieves strong security guarantees while significantly reducing computational and communication overhead, thereby offering a practical and efficient solution for cross-chain PHR sharing in IoMT settings.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Multiagent Systems: Mechanism Design

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies

Abstract

With the proliferation of intelligent healthcare systems, patients’ personal health records (PHR) generated by the Internet of Medical Things (IoMT) in real-time play a vital role in disease diagnosis. The integration of emerging blockchain technologies significantly enhanced the data security inside intelligent medical systems. However, data sharing across different systems based on varied blockchain architectures is still constrained by the unsolved performance and security challenges. This article constructs a cross-chain data sharing scheme, termed MedExChain, which aims to securely share PHR across heterogeneous blockchain systems. The MedExChain scheme ensures that PHR can be shared across chains even under the performance limitations of IoMT devices. Additionally, the scheme incorporates cryptographic reverse firewall (CRF) and a blockchain audit mechanism to defend against both internal and external security threats. The robustness of our scheme is validated through BAN logic, Scyther tool, chosen plaintext attack (CPA) and algorithm substitution attack (ASA) security analysis verification. Extensive evaluations demonstrate that MedExChain significantly minimizes computation and communication overhead, making it suitable for IoMT devices and fostering the efficient circulation of PHR across diverse blockchain systems.

Problem

• PHR sharing
• heterogeneous blockchains
• cross-chain
• IoMT
• data security

Innovation

• Cross-chain
• Personal Health Records (PHR)
• Cryptographic Reverse Firewall (CRF)
• IoMT
• Blockchain Audit