With the rapid advancement of quantum computing, traditional cryptographic techniques are at risk of devolution, necessitating quantum-resilient alternatives for future communication networks. This systematic literature review evaluates the role of Quantum Key Distribution (QKD) in enhancing the security of sixth-generation (6G) wireless communications. Employing the PRISMA methodology, 48 peer-reviewed studies published between 2016 and May 2025 were identified and analyzed. The review addresses three key research questions: the identification of QKD protocols applicable to 6G, challenges in their integration, and proposed solutions for seamless deployment. Findings reveal that protocols such as BB84, E91, CV-QKD, and MDI-QKD, transmitted via optical fiber and satellite channels, offer promising security guarantees. This review concludes that while QKD can significantly strengthen 6G communications against quantum threats, further interdisciplinary efforts in hardware development, standardization, and pilot implementations are essential. The study offers valuable insights for researchers, engineers, and policymakers working toward secure, quantum-resistant future networks. The study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to ensure transparency, rigor, and reproducibility. A comprehensive search was conducted across major scientific databases, including IEEE Xplore, SpringerLink, ScienceDirect, and arXiv, using well-defined keywords and Boolean search strategies related to QKD, 6G networks, and quantum communication security. After removing duplicates and applying predefined inclusion and exclusion criteria, a total of 48 peer-reviewed studies published between 2016 and May 2025 were selected for detailed analysis. The selected literature was systematically classified to address three primary research questions: (i) identification of QKD protocols and technologies applicable to 6G networks, (ii) challenges hindering the integration of QKD into 6G architectures, and (iii) solutions and frameworks proposed to facilitate practical deployment. The findings reveal that prominent QKD protocols, including BB84, E91, Continuous-Variable QKD (CV-QKD), and Measurement-Device-Independent QKD (MDI-QKD), demonstrate strong potential for securing 6G communications when deployed over optical fiber and satellite-based channels. However, practical integration faces significant challenges such as scalability limitations, synchronization issues, quantum channel coexistence with classical networks, hardware complexity, and high deployment costs. The review further highlights emerging solutions that leverage Software-Defined Networking (SDN), Network Function Virtualization (NFV), blockchain-based key management, and hybrid classical-quantum security architectures to overcome these obstacles. Ongoing standardization efforts by organizations such as NIST, ETSI, and ITU-T are also identified as critical enablers for real-world adoption .
With the rapid advancement of quantum computing, traditional cryptographic techniques are at risk of devolution, necessitating quantum-resilient alternatives for future communication networks. This systematic literature review evaluates the role of Quantum Key Distribution (QKD) in enhancing the security of sixth-generation (6G) wireless communications. Employing the PRISMA methodology, 48 peer-reviewed studies published between 2016 and May 2025 were identified and analyzed. The review addresses three key research questions: the identification of QKD protocols applicable to 6G, challenges in their integration, and proposed solutions for seamless deployment. Findings reveal that protocols such as BB84, E91, CV-QKD, and MDI-QKD, transmitted via optical fiber and satellite channels, offer promising security guarantees. This review concludes that while QKD can significantly strengthen 6G communications against quantum threats, further interdisciplinary efforts in hardware development, standardization, and pilot implementations are essential. The study offers valuable insights for researchers, engineers, and policymakers working toward secure, quantum-resistant future networks. The study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to ensure transparency, rigor, and reproducibility. A comprehensive search was conducted across major scientific databases, including IEEE Xplore, SpringerLink, ScienceDirect, and arXiv, using well-defined keywords and Boolean search strategies related to QKD, 6G networks, and quantum communication security. After removing duplicates and applying predefined inclusion and exclusion criteria, a total of 48 peer-reviewed studies published between 2016 and May 2025 were selected for detailed analysis. The selected literature was systematically classified to address three primary research questions: (i) identification of QKD protocols and technologies applicable to 6G networks, (ii) challenges hindering the integration of QKD into 6G architectures, and (iii) solutions and frameworks proposed to facilitate practical deployment. The findings reveal that prominent QKD protocols, including BB84, E91, Continuous-Variable QKD (CV-QKD), and Measurement-Device-Independent QKD (MDI-QKD), demonstrate strong potential for securing 6G communications when deployed over optical fiber and satellite-based channels. However, practical integration faces significant challenges such as scalability limitations, synchronization issues, quantum channel coexistence with classical networks, hardware complexity, and high deployment costs. The review further highlights emerging solutions that leverage Software-Defined Networking (SDN), Network Function Virtualization (NFV), blockchain-based key management, and hybrid classical-quantum security architectures to overcome these obstacles. Ongoing standardization efforts by organizations such as NIST, ETSI, and ITU-T are also identified as critical enablers for real-world adoption .
The emergence of the Quantum computing technologies is imposing greater threats on the existing cryptographic algorithms that rely heavily on the mathematical problems, creating a growing demand for quantum safe Communication. Even though Quantum Key Distribution (QKD) is a theoretically proven secure key exchange method against quantum attacks, it also faces several deployment challenges like scalability, cost, and interoperability limitations. A systematic review was conducted to examine the recent advancements in QKD technologies by analyzing the peer reviewed studies Published between 2021 to 2025 and classified according to protocol design, network architecture and deployment readiness. The review analyzed articles for a Comparison of the recent advancements in the field of Twin Field QKD, Continuous Variable QKD, Hybrid classical quantum networks and long-distance secure communication systems. Furthermore, the review also examined the Conjunction of QKD with the emerging security applications of 5G Networks, IOT environments, edge computing, fog Computing and Multimedia security systems. Despite of the significant technological advancements, the deployment of QKD is still under the constraints of scalability, lower key generation rates, cost of deployment, Synchronization issues, stability complexities, interoperability problems and standardization issues. Through a comprehensive evaluation of QKD protocols and network architectures, this study highlights the critical research gaps and provides future directions for the practical deployment of the QKD enabled secure communication networks.
Abstract The increasing demand for secure communications in mobile and critical infrastructure networks has led to the emergence of Quantum Key Distribution (QKD) as a promising technique for enhancing cryptographic security in next-generation systems. This paper reviews recent progress in integrating QKD within mobile and wireless networks. It focuses on key enabling technologies, such as Software-Defined Networking (SDN), satellite-based, and aerial networks. The paper critically analyzes how these frameworks can address evolving security requirements in sixth-generation (6G) networks and smart city infrastructures. Additionally, it examines the role of Machine Learning (ML) in improving QKD performance and adaptability. Challenges such as key management, mobility support, scalability, and interoperability are explored. These challenges help identify current barriers and research directions. By consolidating developments and highlighting unresolved issues, this study offers researchers valuable insights. It discusses the convergence of quantum communication and advanced mobile architectures, facilitating the design of secure and resilient future communication infrastructures.
By leveraging the fundamental principles of quantum mechanics, quantum cryptography represents a paradigm shift in secure communication by providing information-theoretic security, where any eavesdropping attempt can be intrinsically detected, and by offering resistance to computational attacks, including those posed by future quantum computers that threaten classical cryptographic schemes. To establish Quantum Key Distribution (QKD) as a significant tool in cybersecurity, this study examines the foundational principles of quantum cryptography, focusing on quantum algorithms, quantum bits, and quantum gates. We examine the fundamental QKD protocols and conduct a comparative study of prominent QKD protocols, including BB84, B92, E91, B92, SARG04, COW, Continuous Variable, Six State, Device Independent, and advanced protocols such as MDI-QKD and Twin-Field QKD, to evaluate key rate, distance, and security parameters. A systematic review of the literature has been conducted on the evolution of QKD protocols and networks, QKD integration with advanced technologies like blockchain, IoT, and machine learning, and the practical deployment of quantum communication is studied in this paper. The integration of AI and ML into QKD systems is investigated to explain future algorithm development and performance improvements. Also the function of QKD in quantum networks and the Internet of Things (IoT) is assessed. This paper further delves into the operation of quantum networks, detailing the roles of quantum relays, routers, repeaters, and Free Space Optics (FSO) in enhancing the efficiency and scalability of QKD. Assessing simulators such as SimulaQron, Qiskit, QuNetSim, and QKDNetSim, offering a perception into experimental implementation and protocol validation, resolves the difficulties in quantum-secured communication systems. At last, some security threats are discussed, including Laser damage, Trojan horse attacks, photon-number splitting, and detector blinding, for mitigation of risk strategies. Overall, this work contributes to the importance of QKD and quantum networks in shaping the future of secure wireless communication.
Quantum Key Distribution (QKD) protocols offer a revolutionary approach to secure communication, leveraging the principles of quantum mechanics to enable theoretically unbreakable encryption. This comprehensive review examines the security and efficiency of various QKD protocols, including BB84, E91, and Continuous Variable QKD. We analyze the fundamental principles underpinning these protocols, their implementation challenges, and the practical considerations for real-world deployment. Special emphasis is placed on the security proofs of QKD, addressing potential vulnerabilities such as photon number splitting attacks and detector blinding attacks. Additionally, we explore the efficiency of QKD systems in terms of key generation rates, distance limitations, and integration with existing communication infrastructures. Recent advancements in QKD technology, including satellite-based QKD and quantum repeaters, are also discussed. Our findings highlight the critical role of QKD in future-proofing communication security and the ongoing efforts to enhance its practicality and scalability. This review aims to provide a detailed understanding of the current state of QKD protocols, offering insights into their potential to transform secure communications in the quantum era.
Quantum Key Distribution (QKD) constitutes one of the most profound practical applications of quantum mechanics, enabling two parties to exchange cryptographic keys whose security is guaranteed by the fundamental laws of physics rather than the assumed computational hardness of mathematical problems. As quantum computing capabilities continue to advance, classical public-key infrastructure faces an existential threat, rendering QKD a critical component of post-quantum secure communication architectures. This paper presents a comprehensive survey of QKD spanning foundational protocols, rigorous security proofs, hardware implementation challenges, deployment experiences across metropolitan fiber networks, and recent satellite-based experiments. We analyze the BB84, E91, B92, SARG04, continuous-variable, measurement-device-independent (MDI-QKD), and twin-field (TF-QKD) protocols in depth, examining their security assumptions, achievable key rates, and practical limitations. Particular attention is given to side-channel vulnerabilities in realistic implementations, decoy-state methods for mitigating photon-number-splitting attacks, and finite-key security analysis. We review key performance benchmarks from commercial systems and discuss integration with classical network infrastructure. The paper concludes by identifying open challenges in quantum repeater development, satellite QKD scalability, and standardization efforts essential for large-scale deployment.
With the considerable progress of sixth-generation (6G) networks further on the horizon, security has attracted much attention in the face of increasingly sophisticated threats, especially from quantum computing. Classical cryptographic schemes based on computational hardness are becoming more and more brittle, as they can easily be attacked with a quantum computer. Quantum Key Distribution (QKD) arises as a promising tool for information-theoretic security through quantum mechanics to obtain an unbreakable key by exchanging unknown bit sequences. In this paper, we provide an extensive survey on the integration of QKD both in the envisioned 6G architecture, including current implementations, technical feasibility, and deployment of QKD in fiber-based and wireless scenarios. We compare performance metrics of QKD systems in simulating 6G systems such as secret key rates, quantum bit error rates, and robustness to noise and mobility. We propose and investigate hybrid security schemes to leverage both classical PQC and QKD technologies to build multilayered security shields. We highlight the importance of the Artificial Intelligence (AI) and Machine Learning (ML) in improving QKD systems in terms of smart error correction, dynamic routing, anomaly detection, and adaptive key management, and more. In spite of efforts, the paper points out important research challenges that remain to be addressed in scalability, standardization, cross-operation comparison and demonstration. We finally summarize new directions for quantum-secured networking, offering a future research agenda which combines AI, standardization works and real testbeds to deliver a QKD shift from a lab-scale proof of concept to global-scale 6G network adoption. This review serves as a useful reference for researchers and practitioners as they develop quantum-safe, next-generation communication networks.