As quantum computing advances, existing cryptographic techniques used in smart city infrastructures face increasing vulnerability, especially within internet of things (IoT) networks. This chapter explores the critical role of post-quantum cryptography (PQC) in securing urban IoT ecosystems against quantum threats while addressing sustainability challenges. It covers PQC principles, algorithm families, integration with IoT communication protocols, and the protection of critical sectors such as energy, healthcare, and transportation. The chapter also explores quantum-specific network attacks, supply chain vulnerabilities, and the role of green cryptography and AI-assisted security. Emphasis is placed on balancing quantum resilience with energy efficiency to ensure secure, scalable, and sustainable smart cities. The chapter concludes by identifying future research directions to guide the transition toward quantum-safe and eco-conscious urban infrastructure.
As quantum computing advances, existing cryptographic techniques used in smart city infrastructures face increasing vulnerability, especially within internet of things (IoT) networks. This chapter explores the critical role of post-quantum cryptography (PQC) in securing urban IoT ecosystems against quantum threats while addressing sustainability challenges. It covers PQC principles, algorithm families, integration with IoT communication protocols, and the protection of critical sectors such as energy, healthcare, and transportation. The chapter also explores quantum-specific network attacks, supply chain vulnerabilities, and the role of green cryptography and AI-assisted security. Emphasis is placed on balancing quantum resilience with energy efficiency to ensure secure, scalable, and sustainable smart cities. The chapter concludes by identifying future research directions to guide the transition toward quantum-safe and eco-conscious urban infrastructure.
The emergence of quantum computing poses significant threats to classical cryptographic systems, particularly in smart urban environments powered by the internet of things (IoT). This chapter explores the sustainability aspects and future prospects of integrating post-quantum cryptography (PQC) into IoT-based infrastructures. It examines various PQC algorithms, their deployment challenges in resource-constrained devices, and the trade-offs between energy efficiency, performance, and security. The chapter also highlights quantum-specific threats, including communication vulnerabilities and supply chain risks, and emphasizes sustainable strategies such as lightweight cryptography, hybrid models, green computing paradigms, and AI-based optimization. Future research directions call for energy-efficient algorithm design, cryptographic hardware co-development, and multidisciplinary collaboration. The study underscores the importance of aligning cryptographic resilience with long-term sustainability goals in smart city systems.
The Internet of Things (IoT) is involved in almost every industry, paving the way for innovative applications, including smart cities, intelligent systems, smart homes, smart agriculture, healthcare, and more. However, due to their asset value, these applications are under continuous and evolving cyberattacks. Furthermore, the advent of quantum computing presents a severe threat to traditional cryptographic methods that typically secure IoT systems, potentially rendering existing security mechanisms ineffective against quantum-enabled attacks. To tackle quantum-enabled and traditional cyberattacks, post-quantum cryptography (PQC) has emerged as a promising solution for providing future-proof security for IoT devices and networks against the quantum computing threat. PQC algorithms can resist cyberattacks from classical and quantum computers, ensuring long-term security solutions. This article explores the integration of PQC into practical IoT systems. It highlights the vulnerabilities of classical cryptographic methods and the necessity of transitioning to quantum-resistant solutions. Moreover, the implementation of PQC on IoT systems is analyzed. By proactively exploring the opportunities and challenges associated with PQC, this research lays out future directions for implementing robust, scalable, and secure IoT systems.
As cities adopt integrated IoT ecosystems and data-driven urban governance, traditional encryption faces the threat of obsolescence by quantum computing attacks. This chapter explores the application of quantum cryptography in protecting smart urban infrastructure, with a focus on quantum key distribution (QKD), post-quantum algorithms, and hybrid systems. Through an examination of deployments in smart grids, traffic management systems, and public health platforms, we illustrate how quantum-resistant protocols reduce threats of data breaches and spoofing attacks. There are special challenges: scaling QKD to millions of IoT devices will need new network architectures, and integrating with legacy systems will need phased “crypto-agility” plans. The chapter presents a model for incorporating quantum-safe practice into urban design, with an emphasis on inter-disciplinary collaboration among cryptographers, policymakers, and city administrators.
The use of IoT in the building of Smart cities has transformed how urban areas are managed, as people cannot only monitor in real-time but also automate and make decisions that rely on the data they gather. The post-quantum cryptography (PQC) adoption is a very urgent need as the current classical encryption techniques like RSA and ECC can be broken with quantum computers. The chapter discusses PQC usage in the real world, specifically, in terms of smart urban ecosystems and major areas. It includes real-life case studies of PQC pilotage or proposals in quantum-vulnerable settings to make them more resilient. Moreover, the chapter explains the cryptographic algorithms standardized by NIST, assesses their applicability to constrained IoT use, and proposes a Proof of Concept (PoC) architecture of a PQC-enabled smart city. The chapter is an interim between theory and practice and is a part of the overarching topic of quantum-safe and sustainable urban development, and it provides a practical plan to urban planners, technologists, and cybersecurity professionals.
The impending threat posed by quantum computing to classical cryptographic systems has accelerated the need for post-quantum cryptographic (PQC) solutions, particularly within the rapidly expanding domain of the Internet of Things (IoT). As IoT devices operate under severe constraints in terms of memory, processing power, and energy, integrating quantum-resilient algorithms presents both a critical necessity and a formidable challenge. This chapter provides a comprehensive study of PQC implementations on constrained IoT platforms, exploring algorithmic performance, memory consumption, execution time, and energy efficiency across various benchmarking environments. It offers a comparative analysis of bare-metal and RTOSbased deployments, evaluates the trade-offs between security and real-time responsiveness, and investigates power-aware scheduling and duty cycling strategies for secure task execution. Case studies involving smart sensors, medical wearables, and industrial nodes highlight the practical implications and optimizations required for effective PQC integration. Emphasis was placed on hardware-software co-design, library selection, and communication stack alignment to ensure future-ready, quantum-secure IoT deployments. This chapter bridges theoretical cryptographic resilience and applied system-level engineering, laying a foundational framework for scalable and secure post-quantum IoT ecosystems.
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.