Healthcare Is Building for Tomorrow on Security Designed for Yesterday

Healthcare systems are digitizing faster than their security foundations are evolving. Electronic health records, telemedicine platforms, connected medical devices and cross-institutional data exchange have made care more accessible and responsive, but they have also locked highly sensitive information into cryptographic systems that may need to remain trustworthy for decades.

A new systematic review, "Advancing Blockchain and Quantum Technologies for Secure E-Health Systems: A Systematic Review and Conceptual Security Framework," by Abdullah Alabdulatif of Qassim University, published in Electronics, focuses on this long security horizon. Reviewing 57 peer-reviewed studies published between January 2018 and June 2025, the paper examines how blockchain, post-quantum cryptography, quantum key distribution and quantum random number generation could be combined to protect digital healthcare against both present-day cyber risks and future quantum-enabled attacks.

The study argues that healthcare data are unusually long-lived, migration from legacy systems takes years, and attackers can potentially steal encrypted information today in the hope of decrypting it later. Waiting until cryptographically relevant quantum computers arrive could therefore leave institutions with too little time to redesign deeply embedded systems.

Blockchain Secures Health Data, But Its Cryptography Has an Expiry Risk

Blockchain has been attractive to healthcare because it can improve auditability, data integrity, provenance and access control across hospitals, laboratories, insurers, pharmacies and patients. Its distributed architecture can reduce single points of failure and support applications ranging from electronic health records and telemedicine to pharmaceutical tracking and consent management.

However, blockchain does not remove the need for cryptography. Many implementations still rely on mechanisms such as RSA, ECDSA and conventional key exchange to authenticate users and protect transactions. The review argues that sufficiently capable quantum computers could eventually weaken these foundations, particularly through Shor's algorithm, which threatens widely used public-key systems.

In a healthcare setting, the consequences could extend well beyond stolen passwords. Compromised keys could theoretically enable attackers to forge digital signatures, impersonate trusted healthcare entities, manipulate authorization mechanisms or undermine confidence in long-term medical records. The stakes are higher because healthcare information is not only valuable but also safety-critical and often expected to remain confidential for many years.

The paper is more nuanced about symmetric encryption and hash functions. Grover's algorithm does not simply "break" SHA-256; instead, it reduces the effective strength of some brute-force security properties. The study emphasizes that practical impacts vary by blockchain design and that permissioned healthcare ledgers may face different risks from public blockchains.

The Answer Is Not One Quantum Technology but a Layered Security Transition

The study proposes Quantum-Blockchain Security Architecture, or QBSA, designed to combine several forms of protection rather than rely on a single technology. It's based on the logic that future healthcare security will require quantum-safe cryptography at the software layer, stronger key-management systems, trusted data governance and healthcare interoperability working together.

At the cryptographic level, the architecture incorporates NIST-standardized post-quantum algorithms. ML-KEM is proposed for secure key establishment, ML-DSA for transaction signing and SLH-DSA as a longer-term backup signature option. The model also allows conventional and post-quantum algorithms to operate simultaneously during migration, reducing the need for an abrupt switch across large healthcare systems.

Quantum key distribution and quantum random number generation form another part of the architecture. QKD can strengthen secure key exchange between institutions where appropriate infrastructure is available, while QRNG can improve the quality of cryptographic randomness. However, the paper does not present these technologies as universal substitutes for conventional security; infrastructure cost, distance and hardware maturity remain significant constraints.

The blockchain layer is intended to support consent management, secure auditing and multi-institutional governance, while the healthcare application layer connects the architecture to clinical systems and Internet of Medical Things devices. The broader insight is that quantum resilience cannot be added as a narrow encryption upgrade. It has to coexist with patient consent, interoperability standards, institutional trust and operational healthcare workflows.

This integrated approach addresses a weakness the review finds repeatedly in the existing literature. Many proposed systems focus on isolated components, while end-to-end integration of blockchain, post-quantum cryptography, QKD and healthcare interoperability remains limited. Most existing implementations are still conceptual, experimental or prototype-level rather than validated at health-system scale.

Quantum-Safe Healthcare Comes With Real Costs and Hard Trade-Offs

Post-quantum security is stronger against future attacks, but it is not lightweight. Some standardized algorithms require much larger keys and signatures than classical cryptographic schemes. The paper notes, for example, that an ML-DSA-65 signature is dramatically larger than an ECDSA signature, increasing bandwidth, blockchain storage and transaction overhead.

Those trade-offs are especially important for connected medical devices. Wearable sensors, implantable systems and edge devices often operate with limited processing power, memory and energy. Adding computationally demanding post-quantum algorithms could create latency, battery and storage problems precisely in environments where reliability is critical.

This has strong implications for developing countries. Health systems with constrained budgets, uneven digital infrastructure and large rural populations may not be able to adopt expensive quantum communication infrastructure on the same timetable as wealthy health systems. Their more practical pathway may involve crypto-agile software, standardized post-quantum algorithms and phased upgrades before investing in specialized quantum hardware.

Regulation presents another difficult layer. Existing rules such as GDPR and HIPAA were not specifically designed for decentralized, quantum-resilient healthcare architectures. The review highlights unresolved questions around cross-border breaches, immutable records, patient consent, data ownership, quantum-safe retention and accountability when multiple institutions share infrastructure.

The risk, therefore, is not simply that health systems migrate too slowly. Poorly planned migration could also create new problems: higher infrastructure costs, fragmented standards, incompatible systems or security architectures that are technically sophisticated but impractical for frontline healthcare environments.

The Real Policy Challenge Is to Prepare Before the Threat Becomes Urgent

The review suggests that quantum cybersecurity should be treated as a resilience and procurement issue rather than as a distant research problem. Governments and health authorities can begin by identifying where quantum-vulnerable cryptography is embedded in existing systems and ensuring that new infrastructure is designed for crypto-agility: the ability to replace algorithms without rebuilding entire platforms.

Hospitals and technology vendors also need migration strategies that distinguish between different levels of risk. Long-lived medical records and high-value institutional communication may justify earlier protection, while resource-constrained devices may require carefully optimized post-quantum approaches. A blanket migration strategy would ignore the very different computational and operational realities across healthcare environments.

The authors acknowledge important limitations. The review was conducted by a single author, and the proposed QBSA remains conceptual rather than experimentally validated. Much of the underlying evidence is also concentrated in prototypes and early-stage implementations, meaning the architecture should be viewed as a roadmap for testing rather than a proven deployment model.

Future research will need to move rapidly from architecture to operational evidence. The paper calls for real-world testbeds combining post-quantum blockchain systems, IoMT devices, hospital infrastructure and quantum communication components, alongside performance testing covering latency, throughput, memory use, storage growth and energy consumption.

The longer-term significance goes beyond blockchain. The study anticipates a future in which AI-driven analytics, distributed healthcare systems, quantum computing and privacy-preserving technologies increasingly converge. It could support personalized medicine, predictive diagnostics and secure collaborative research, but it will also make cybersecurity architecture more complex and more strategically important.