Quantum communication and quantum computing sit at the intersection of science policy and geopolitics. Quantum communication, especially quantum key distribution (QKD), promises information-theoretic security for key exchange, while quantum computing threatens today’s public key cryptography and promises new capabilities in optimisation, materials, and AI acceleration. Both arenas demand standards, interoperability, and trusted supply chains —making them inherently diplomatic.
Quantum communication and quantum computing sit at the intersection of science policy and geopolitics. Quantum communication, especially quantum key distribution (QKD), promises information-theoretic security for key exchange, while quantum computing threatens today’s public key cryptography and promises new capabilities in optimisation, materials, and AI acceleration. Both arenas demand standards, interoperability, and trusted supply chains —making them inherently diplomatic.
As digital communication continues to expand across critical infrastructures, ensuring data security has become more challenging in the face of advancing computational capabilities, especially with the anticipated rise of quantum computers. Quantum Key Distribution (QKD) presents a revolutionary approach to secure communications by leveraging the fundamental principles of quantum mechanics, such as superposition and entanglement, to enable the secure exchange of cryptographic keys. Unlike classical encryption methods that rely on computational complexity, QKD ensures unconditional security, as any attempt to intercept the key disturbs the quantum state, revealing the presence of eavesdroppers. This paper explores the current developments in QKD protocols, including BB84 and E91, as well as practical challenges in implementation, such as distance limitations and hardware requirements. Furthermore, it discusses recent advancements in satellite-based QKD, integrated photonics, and quantum networks, highlighting their potential to reshape the landscape of secure global communication. The integration of QKD into future communication infrastructure is positioned to be a cornerstone of post-quantum cryptography, making it a vital technology in the era of quantum computing.
Quantum technology, and especially quantum computing, is advancing rapidly. Our every-day secure communication infrastructure relies heavily on public key cryptography; unfortunately, many public key schemes are in fact insecure against quantum algorithms. Furthermore, adversaries who, today, capture information encrypted using classical key distribution systems, can wait and, as soon as quantum computers of sufficient power become available, they may decipher all previously captured information. While some new “post-quantum” public key systems are assumed to be secure against quantum computers, this is only an assumption and, even if the assumption remains valid, still results in systems that are less efficient for end-users than the more commonly used public key systems employed today. While the advent of quantum technology may seem detrimental to security, in fact, one may harness the power of quantum through quantum key distribution (QKD) for stronger security guarantees. Such QKD protocols allow two (or more) parties to establish a shared secret key, secure against an all-powerful adversary. Perhaps surprising is that QKD technology is already here both experimentally and commercially. This tutorial serves as an introduction to basic QKD along with QKD technology from a practical perspective. Quantum communication is a highly interdisciplinary field of research and one of the goals of this article is to introduce a larger set of researchers and practitioners to its study in the hopes of furthering its progress and eventual wide-scale adoption.
The prospect of quantum computing threatens the security of modern encryption methods, putting our private communications at risk. With experts predicting the development of powerful quantum computers as early as the end of the decade, the urgency of transitioning to `quantum-safe’ communications is apparent. There are two classes of solutions available: post-quantum cryptography (PQC), which refers to communication algorithms designed to be safe against quantum computers, and quantum key distribution (QKD), a new technology with unique advantages and challenges. These solutions are not mutually exclusive, and this review argues that they are in fact complementary solutions to the threat of quantum computing. However, QKD has received criticism for being a less practical solution than PQC. This review makes the case for QKD and argues that it offers significant advantages which are not adequately recognised. I conclude that the development of QKD would benefit from increased government support and I provide policy recommendations for how to best support it.
Quantum computing provides the pathway to dismantle the security provided by cryptography especially classical public-key systems due to the emergence of Shor’s algorithm. This emerging threat necessitates the development of new security paradigms that are quantum-resistant. Consequently, two new approaches have emerged as prominent solutions, namely Quantum Key Distribution (QKD), which relies on quantum mechanical principles for security, and Post-Quantum Cryptography (PQC), which relies on classical cryptography for quantum resistance. This paper presents an extensive analysis of the global research trends in quantum cryptography and post-quantum cryptographic algorithms by incorporating the use of both bibliometric analysis and comparative analysis. The paper relies on a dataset collected from the Web of Science database from 2010 to 2025. The findings of the paper demonstrate an increase in scientific production in the field of quantum cryptography, with post-quantum cryptography emerging as a new dominant area coinciding with standardization by NIST, whereas quantum key distribution continues to evolve with new developments in quantum communication.
That large-scale universal quantum computers could break widely used encryption methods is well known, but what was once seen as a distant, even theoretical, problem is now driving the latest technology race. Current developments in advanced quantum cryptographic solutions are discussed, including the use of public and private/secret keys, random number generation (RNG), quantum key distribution (QKD), QuantumCloud and chip-based quantum cryptography communication systems along with protocols and security/trustless computing issues. Some possible applications such as quantum-resistant communication systems for defence aircraft/drones, blockchain, Internet of Things (IoT) and smart city are mentioned. Particular focus is given to satellite-based QKD software architecture and QKD over optical fibre, along with appropriate standards, allowing over globe-spanning distances, to achieve end-to-end secure communication.
Data protection and information security have been the essence of communication in today's digital era. Authentication and secrecy of secure communication are achieved using key-based cryptographic primitives; the security of which significantly relies upon the underlying computationally complex mathematics. Moreover, these existing cryptographic primitives are considered to be non-deterministic on the basis of the existing computational capabilities. However, the considerable advancements in the development of quantum computers have significantly enhanced parallel computations; thereby, posing a great threat to these existing encryption primitives. Thus, in the future, the physical manifestation of a large successful quantum computer is likely to break all the existing public-key encryption algorithms in no time. This has led to a remarkable surge of interest in propelling quantum mechanics into existence; subsequently, leading cryptographers to research various viable domains to offer quantum-resistant secure communications. Resultantly, quantum cryptography/quantum key distribution has emerged as a futuristic replacement for classical cryptography as it offers unconditionally secure communication along with the inherent detection of any unintended user. Thus, keeping in view the significance of this relatively newer domain of cryptography, this research focuses on presenting a consolidated review of the various Quantum Key Distribution (QKD) protocols. A comparative analysis of the working mechanism of the prominent QKD protocols is presented along with an overview of the various emerging trends that have been proposed to optimize the implementational efficiency of the BB84 protocol.