The rapid expansion of autonomous satellite constellations and interplanetary missions demands ultra-secure, decentralized communication frameworks resistant to both classical and quantum attacks. This paper proposes an Entanglement-Assisted Quantum Cryptographic Framework (EAQCF) that integrates quantum entanglement-based key distribution, Decentralized Quantum Trust Consensus (DQTC), and hybrid classical-quantum routing for resilient space communication. The framework enables autonomous key generation and validation among satellite nodes without ground station dependency. Simulation results demonstrate 35-40% improvement in quantum key generation rate, 97.8% successful key exchange at 1,500 km, and effective isolation of compromised nodes through dynamic trust scoring. Compared to conventional QKD systems, EAQCF reduces latency by 23% and maintains 94.6% success rates even under high-noise conditions at 2,000 km. The proposed architecture provides a scalable foundation for secure lunar relays, deep-space missions, and future quantum internet infrastructure.
The rapid expansion of autonomous satellite constellations and interplanetary missions demands ultra-secure, decentralized communication frameworks resistant to both classical and quantum attacks. This paper proposes an Entanglement-Assisted Quantum Cryptographic Framework (EAQCF) that integrates quantum entanglement-based key distribution, Decentralized Quantum Trust Consensus (DQTC), and hybrid classical-quantum routing for resilient space communication. The framework enables autonomous key generation and validation among satellite nodes without ground station dependency. Simulation results demonstrate 35-40% improvement in quantum key generation rate, 97.8% successful key exchange at 1,500 km, and effective isolation of compromised nodes through dynamic trust scoring. Compared to conventional QKD systems, EAQCF reduces latency by 23% and maintains 94.6% success rates even under high-noise conditions at 2,000 km. The proposed architecture provides a scalable foundation for secure lunar relays, deep-space missions, and future quantum internet infrastructure.
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.
Establishing information-theoretically secure communication between arbitrary locations on Earth is a central goal of quantum networking, for which space-based distribution of quantum entanglement is a leading approach. Modelling and analysis of the performance of satellite entanglement pair distribution is therefore important for the architecture and design of future constellations and space systems. However, entanglement-based quantum key distribution in the absence of quantum repeaters, is especially prone to finite-key effects due to low coincident count rates compared to trusted-node single-path links. Quantifying these effects under realistic orbital conditions is therefore essential for the design of practical satellite quantum communication systems. Here, we develop a high-fidelity model of pair distribution from a low-Earth-orbit satellite that captures orbital dynamics, elevation-dependent loss, background noise, and extraneous detector effects. Integrating this with a finite-key security framework for the BBM92 protocol, we optimise the secret key length across different overpass geometries, orbital altitudes, and optical ground station (OGS) separations. We show that secure key generation remains feasible in early clear daytime conditions using baseline parameters representative of current technologies, while showing that modest system improvements could further extend daytime operation. Finally, we evaluate the annual secret key performance for representative intercity-scale OGS pairings. Our results provide quantitative performance bounds and practical design guidelines for near-term entanglement-based satellite QKD, enabling informed trade-offs between satellite payload complexity, ground infrastructure, and achievable secure key throughput.
Global satellite infrastructure has transformed maritime data links, allowing ships to share real-time details—such as location, speed, and environmental readings—with orbiting platforms. Yet conventional encryption methods can be compromised, threatening the confidentiality of these exchanges. Quantum Key Distribution (QKD) inherently detects any interception during key setup, offering a robust security layer. In our Satellite Vehicular Communication (SVC) framework, we integrate two entanglement-based QKD protocols: BBM92, which uses satellite-generated entangled photon pairs, and Measurement-Device-Independent QKD, which removes trust assumptions from the measurement hardware. We evaluate performance over free-space optical paths up to 25 km under realistic noise and weather scenarios. Findings show that MDIQKD achieves higher raw key generation rates but experiences rising quantum bit error rates at extended ranges, whereas BBM92 delivers lower error rates and steadier secure key throughput at moderate distances.
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.
Quantum Key Distribution (QKD) offers a fundamentally secure method for key exchange, grounded in the principles of quantum mechanics rather than computational complexity. As advancements in quantum computing threaten classical cryptographic systems (such as RSA) QKD presents itself as a crucial technology for future secure communications. Among the primary challenges for global-scale QKD is the limited range of optical fiber channels, making satellite-based free-space optical links an attractive alternative. QKD presents unique constraints related to the short and unreliable communication windows, due to atmospheric conditions and the presence of sunlight, which makes the real time operation of QKD constellations almost impossible. Traditional configurations offering instantaneous global coverage, such as Walker constellations, are not necessary for QKD networks and other constellation designs may be explored. In this work, we present as an alternative a two-height, single orbital plane constellation, which facilitates regular and extended inter-satellite visibility, enabling the constellation to function as a virtual trusted node and increasing network capacity and flexibility. The main technical contribution is the development of a simulation tool designed to evaluate and optimize satellite QKD constellations. The simulator allows researchers and mission planners to assess key generation rates and overall system performance, helping to reduce the risks, costs, and uncertainties involved in satellite deployment. Our approach provides a powerful framework for advancing the development of scalable and efficient global QKD networks.
The emergence of sixth-generation (6 G) wireless networks and the rapid development of Quantum Internet infrastructure have created unprecedented demands for ultrasecure communication. Classical cryptographic techniques, which depend on computational hardness, are vulnerable to quantum attacks enabled by powerful quantum algorithms. Quantum cryptography, particularly Quantum Key Distribution (QKD), offers information-theoretic security based on the principles of quantum mechanics, making it a foundational element for future network security. This paper investigates the integration of quantum cryptography within 6 G architectures and Quantum Internet frameworks, focusing on secure key exchange, entanglementassisted communication, and quantum-safe protocols. We analyze the challenges posed by channel loss, quantum repeater limitations, hardware constraints, and large-scale deployment in ultra-dense 6 G environments. Our study highlights the potential of hybrid quantum-classical security models and outlines how quantum cryptography can support resilient, scalable, and next-generation secure communication systems.