Quantum-Safe Block chain System for Privacy-Preserving Medical Record Sharing

Abstract

The swift computerization of healthcare systems has the impact that medical data have become highly efficient, available, and interoperable. Nonetheless, it has also brought about acute security threats, such as unauthorized access, data breach, ransomware attacks, insider threats and data manipulation. RSA and Elliptic Curve Cryptography (ECC) are traditional cryptographic, which are exposed to the new quantum computing threats, to protect electronic health records (EHRs). The quantum algorithms such as Shor algorithm can break the classical encryption schemes leading to an immediate requirement of the next generation quantum-resistant security frameworks. To overcome this issue, this study offers a Quantum Resilient Blockchain Architecture (QRBA), which will be used to ensure that medical records are managed in the post-quantum age. The suggested architecture also incorporates the use of blockchain technology and post-quantum cryptographic (PQC) methods to assure the long-term data confidentiality, integrity, authenticity, and availability. In blockchain offers a decentralized, tamper-resistant infrastructure that is transparent and auditable, and quantum-resistant cryptography (lattice-based, hash-based, and code-based algorithms) substitutes the conventional public-key systems. The framework uses a hybrid encryption model in which symmetric encryption will be applied to ensure a secure data storage and post-quantum digital signatures will be implemented to ensure authentication and identity verification. Smart contracts are applied to secure access control, patient consent management and efficient data-sharing between healthcare stakeholders i.e. hospitals, laboratories, insurance providers, and regulatory authorities. Scalability and regulatory compliance In order to meet standards like HIPAA and GDPR, the system will be based on a permissioned blockchain model. The off-chain storage of sensitive medical data is encrypted in the distributed storage systems, and only reference hash and metadata are stored on-chain to decrease storage overhead. The architecture also discusses the implementation of Quantum Key Distribution (QKD) in a secured key exchange in the future. Smart contracts enforce role-based and attribute-based access control mechanisms in order to offer fine-grained security. System analysis shows that the suggested architecture will be highly resistant to common classical and quantum cyber threats, improve medical record handling transparency, and remove single points of failure that are characteristic of centralised systems. According to simulation findings, post-quantum cryptographic techniques have some computational overhead, but optimized implementation guarantees satisfactory performance in real-time healthcare processes. In sum, it can be stated that the Quantum Resilient Blockchain Architecture is a secure, scalable and future-ready solution to the challenges of protecting sensitive healthcare data without compromising on efficiency, regulatory compliance, and patient trust.