The ever-increasing quantum computational power may pose a serious threat to classical Public Key Exchange (PKE) algorithms in the next few years. The need for quantum resilient key exchange schemes is becoming more topical as quantum computers become more powerful. Quantum Key Distribution (QKD) promises unconditionally secure key distribution between two remote parties. The distilled keys of a QKD link can be used by classical symmetric algorithms such as the Advanced Encryption Standard (AES). Unfortunately, QKD has come across some major limitations in distance reach and Secure Key Rates (SKR)s that make the idea of a global quantum secured network debatable. In this work, we propose a satellite assisted Key Encapsulation Mechanism (KEM) that takes advantage of the high security of a quantum AES-256-bit key encrypted link, to deliver secret keys through classical communication layer in high rates, using QKD only for link establishment. In this way, the keys produced by the QKD do not directly encrypt the data traffic, allowing therefore longer lifespans. This scheme would be able to support up to thousands terminal nodes with a total average SKR as low as 4.23 bps.
The ever-increasing quantum computational power may pose a serious threat to classical Public Key Exchange (PKE) algorithms in the next few years. The need for quantum resilient key exchange schemes is becoming more topical as quantum computers become more powerful. Quantum Key Distribution (QKD) promises unconditionally secure key distribution between two remote parties. The distilled keys of a QKD link can be used by classical symmetric algorithms such as the Advanced Encryption Standard (AES). Unfortunately, QKD has come across some major limitations in distance reach and Secure Key Rates (SKR)s that make the idea of a global quantum secured network debatable. In this work, we propose a satellite assisted Key Encapsulation Mechanism (KEM) that takes advantage of the high security of a quantum AES-256-bit key encrypted link, to deliver secret keys through classical communication layer in high rates, using QKD only for link establishment. In this way, the keys produced by the QKD do not directly encrypt the data traffic, allowing therefore longer lifespans. This scheme would be able to support up to thousands terminal nodes with a total average SKR as low as 4.23 bps.
There has been a dramatic increase in the number of Internet of Things (IoT) devices and their applications. Furthermore, there is a growing impetus to integrate IoT networks on a global scale, using satellites to expand the range of IoT connectivity into geographically remote areas. Ensuring the security of satellite backhaul for IoT networks is thus of paramount importance. The steady advance of quantum computing in recent years threatens to nullify classical cryptographic approaches based on assumptions of computational hardness, motivating the need for post-quantum cryptography. Quantum computing algorithms have been developed that, once a quantum computer of sufficient scale is realised, will be able to break classical cryptosystems efficiently (at polynomial-time complexity). A promising method of securing information against this threat at the physical layer has emerged in the form of quantum key distribution (QKD). QKD exploits the fundamental physical properties of light to guarantee information-theoretic security. Research into the application and standardisation of QKD to secure satellite backhaul, however, is still in its infancy. This paper presents a brief overview of the theoretical basis for QKD, whilst also providing a survey of contemporary QKD protocols. It evaluates the ability of these protocols to secure satellite backhaul in the context of a typical satellite-IoT network architecture. Furthermore, it highlights the vulnerabilities, as well as the technical challenges associated with this endeavour. Finally, it proposes directions for future research and development into protocols and standardisation for the satellite-integrated IoT domain. Several challenges must be overcome before QKD can evolve into a global-scale solution for securing satellite-IoT. Secret key generation rate remains very low in practical demonstrations of trusted-relay QKD satellite architectures. Further research is needed to overcome or mitigate the fundamental rate-distance trade-off before satellite QKD can be considered practicable in an IoT application. Alternatives that do not rely on trusted nodes are contingent on nascent technologies such as quantum repeaters and quantum memory. Whilst in theory QKD provides perfect information-theoretic security, it remains vulnerable to attacks that exploit imperfections in real-world equipment. Further effort is needed to develop QKD protocols that can safeguard against the aforementioned challenges.
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 computers pose a long-term threat to many currently used cryptographic schemes as they are able to efficiently solve the computational problems those schemes are based on. This threat has lead to research into quantum-resistant cryptographic schemes to eventually replace those currently used, as well as research into how to ease the transition from classical schemes to quantum-resistant ones. One approach to address these issues is to use a combiner that creates hybrid schemes, that is schemes which are classically and quantum-resistant, to protect against quantum attacks and maintain current security guarantees. Such combiners are used as a way to provide trust from different schemes and their differing computational difficulty assumptions rather than a single scheme. which may later become vulnerable. An important type of scheme that must be secure against both classical and quantum attacks are key encapsulation mechanisms (KEMs), as they are commonly used for constructing public-key encryption and key exchange protocols. We first define new security notions for KEMs modeling attackers of various levels of quantum power ranging from fully classical to fully quantum. We then construct a combiner that creates hybrid schemes for key encapsulation mechanisms which is secure against adversaries with varying levels of quantum power over time and can be implemented efficiently. Our construction provides an efficient method to combine KEMs using an additional scheme. This construction is also general enough that it can be implemented in settings such as key exchange protocols, like those used in the Transport Layer Security (TLS) protocol for web browsers, without affecting existing structure meaningfully.
In recent years, quantum-based communication is emerging as a new technique for ensuring secured communications because it can guarantee absolute security between two different remote entities. Quantum communication performs the transmission and exchange of quantum information among distant nodes within a network. Quantum key distribution (QKD) is a methodology for generating and distributing random encryption keys using the principles of quantum physics. In this paper, we investigate the techniques on how to efficiently use QKD in 3D satellite networks and propose an effective method to overcome its communications-distance limitations. In order to implement secured and reliable communications over wireless satellite links, we develop a free-space quantum channel model in satellite communication networks. To enlarge the communications distances over 3D satellite networks, we propose to employ the intermediate nodes to relay the unconditional keys and guarantee the Quantum Bit Error Rate (QBER) for security requirement over 3D satellite networks. We also propose the communication model for QKD security-Quality of Service (QoS) guarantee and an adaptive cooperative routing selection scheme to optimize the throughput performance of QKD-based satellite communications networks. The obtained simulation results verify our proposed schemes.
The existence of quantum computing presents an existential threat to the traditional cryptographic algorithms, and there is a need to create communication mechanisms that are fundamentally secure. In this regard, the concept of Quantum Key Distribution (QKD) provides information-theoretic security, which is founded on quantum mechanics. Nevertheless, conventional QKD protocols have serious shortcomings such as lack of distance in communication, vulnerability to side-channel attacks, and inability to support the large-scale heterogeneous network. We suggest that HQNet-QKD a Hybrid Quantum Key Distribution framework can help solve these issues by offering a more secure, scalable and future-proof key exchange framework in hybrid classical-quantum networks. To support multi-layered security, the proposed architecture is a network ensuring the smoothness of decoy-state BB84, Measurement-Device-Independent QKD (MDI-QKD), entanglement/twin-field-based QKD with verifiable Secret Sharing (VSS) and Post-Quantum Cryptography (PQC). It provides a complete methodology such as system architecture, mathematical modeling, and end-to-end key synthesis. When used over a distance of 300 km, simulation and testing have shown that HQNet-QKD can achieve up to2.7×higher secret key rate (SKR) than conventional methods, secret communication at 700 km and resilience to both quantum and classical attacks more than 96%. In addition, the framework guarantees forward secrecy, detector-side immunity, contextbound key derivation, and composability and thus resistant to current and future adversaries. It has a low-computational overhead modular design, making it trivial to deploy in a real world, in applications like quantum-secured 5G backbones, cloud data centers, critical infrastructure, and satellite-based communication systems. The findings make HQNet-QKD a new generation solution to quantum-safe secure communication and the first step towards the implementation of the quantum internet.
With the rapid advancement of Low Earth Orbit (LEO) satellite constellations, ensuring the security of satellite-to-ground communication has become a critical concern. Traditional cryptographic techniques, while effective against classical attacks, face increasing threats from quantum computing. This paper proposes a quantum key secure transmission method tailored for LEO satellite-ground communication scenarios. The method integrates quantum key distribution (QKD) with dynamic channel estimation and orbital mobility prediction to support secure and low-latency key handshakes between satellites and ground stations. A hybrid encryption strategy is introduced, where QKD-generated keys are used to refresh symmetric session keys in real time, significantly enhancing resistance to eavesdropping and man-in-the-middle attacks. Simulation results demonstrate that the proposed method ensures stable key distribution under Doppler-shifted and intermittent link conditions, achieving improved secrecy capacity and resilience against quantum-level adversaries. This work provides a viable and scalable quantum-safe communication solution for future secure satellite networks.