Quantum-Secure Healthcare: A Comprehensive Review of Post-Quantum Cryptography and Cyber Defense in IoMT

The increasing digitalization of the healthcare system, driven by the use of electronic health records, medical IoT devices, and AI-aided diagnostics, has significantly expanded the attack surface for cyber threats. Even though current crypto-graphic protocols provide sufficient security against classical adversaries, new developments in quantum computing threaten the confidentiality, integrity, and availability of medical information as never before. Shor’s and Grover’s quantum algorithms can breach extensive asymmetric and symmetric encryption systems, rendering modern healthcare security systems obsolete. The re-view consists of an in-depth and organized analysis of the dynamic quantum threat environment in the context of healthcare ecosystems and the need to move towards quantum-resilient security architectures. The paper provides a synthesis of the existing literature on post-quantum cryptography (PQC), noting lattice-based, hash-based, multivariate, and code-based algorithms as potentially viable long-term replacements for cryptography. Moreover, we examine the cybersecurity issues associated with quantum-enabled attacks of medical IoT systems, clinical decision-support systems, wearable sensors, telemedicine systems, and cloud-based health information exchanges. Another aspect of quantum-classical defense mechanisms examined in the review is hybrid quantum-classical defenses, quantum key distribution (QKD), quantum random number generation (QRNG), and blockchain-based trust systems aimed at making systems resilient to advanced persistent quantum attacks. This paper identifies key gaps and outlines future research directions for developing quantum-secure medical systems, drawing on trends in cryptography, quantum computation, and healthcare cybersecurity. The results highlight the importance of early implementation of PQC standards and a layered cyber defense approach to protect patient privacy, ensure regulatory compliance, and retain trust in next-generation digital medical settings.