Systematic review on securing IoT systems with post quantum cryptography emerging threats, countermeasures, and future research needs

The rapid deployment of Internet of Things (IoT) devices across critical infrastructure’s sectors such as healthcare, transportation, and smart cities brings unprecedented security challenges; particularly as quantum computing threatens the classical cryptography. This systematic review analyzes IoT security in relation to post-quantum cryptography (PQC), highlighting vulnerabilities, evolving threat, and cryptographic countermeasures. Using the PRISMA 2020 protocol, our work employed a rigorous and reproducible search strategy, where the initial Boolean query, ((“IoT” OR “Internet of Things”) AND (“Cryptography” OR “Encryption Scheme”) AND “Quantum”), was developed and effectively customized for nine reputable databases to maximize the coverage. From an initial pool of 5,151 publications dated between 2020 and February 12, 2025, a content-based screening was conducted at the title, abstract, and full-text levels. This meticulous filtering resulted in a final corpus of 161 studies deemed relevant for in-depth analysis and synthesis. Then, we categorize and analyze PQC algorithms by vulnerabilities, suitability for resource-constrained IoT environments, performance evaluation, scalability, and quantum resilience. We also identify key limitations in implementations of current cryptographic schemes, including issues in key management and authentication; and outline major challenges such as resource constraints of IoT devices, environmental noise, quantum reversible computing, security vulnerabilities, quantum hardware constraints, and complexities in integration. To counter these threats, we propose a framework of PQC countermeasures and illustrated by a hypothetical case study of PQC adoption in a real-world IoT system. Finally, we propose future research directions in lightweight PQC, hybrid frameworks, improved key management and distribution, addressing quantum distance matters, countering quantum threats, and standardization for IoT environments.