This paper proposes a quantum k-nearest neighbor (QkNN)-based multiclass attack detection framework for CVQKD systems that establishes a direct connection between attack detection and secret key generation, enabling a more realistic security evaluation for practical CVQKD systems.
Abstract
Continuous-variablequantum key distribution (CVQKD) enables information-theoretically secure communications between two legitimate users. However, practical CVQKD systems remain vulnerable to various attacks, while existing machine-learning-based detection schemes suffer from increasing computational complexity when processing large-scale monitoring data. In this paper, we propose a quantum k-nearest neighbor (QkNN)-based multiclass attack detection framework for CVQKD systems. Specifically, physical features extracted from Bob’s monitoring data are encoded into quantum states and subsequently classified using the QkNN algorithm to identify different attack behaviors. Furthermore, by incorporating the attack ratio, retained-data ratio, and attack detection performance into secret key rate analysis, an attack-aware secret key rate model is established to characterize the influence of practical attacks on key generation. Simulation results demonstrate that the proposed scheme achieves high attack classification accuracy while significantly reducing computational complexity. Moreover, the proposed framework establishes a direct connection between attack detection and secret key generation, enabling a more realistic security evaluation for practical CVQKD systems.
A dynamic evolutionary attack detection scheme for practical QKD, in which Eve’s attack feature could be vectorized by a well-designed embedding model and dynamically self-update to an attack feature vector database, which significantly improves the generalization capability of quantum attack detection and promotes the practical development of QKD.
Minjie Liu, Ye Chen, Xiaodong Fan et al.· Science China Information Sc...· 0 citations
Continuous-variable quantum key distribution (CVQKD) has attracted extensive attention due to its compatibility and low costs. However, bandwidth mismatch exists to varying degrees between the transmitter and receiver. This may prevent frequency components carrying modulation information from being fully perceived by the legitimate party. In this paper, we identify a practical security loophole caused by bandwidth mismatch and propose a corresponding spectral attack scheme. Different from previous approaches that exploit security loopholes to conceal the excess noise introduced by intercept-resend attacks, this scheme can directly obtain raw-key information without introducing additional disturbances. A proof-of-principle attack on a CVQKD system with filtering operation is constructed to verify the feasibility. Experimental results indicate that Eve can obtain enough information to render the system insecure if this practical security loophole is ignored. Based on the identified security loophole, corresponding defense strategies are proposed. This work helps bridge the gap between theoretical models and practical implementations, providing a reference for defense design in practical quantum communication systems.
Chen Gong, Mingxuan Guo, P. Huang et al.· 0 citations
Federated Learning (FL) enables collaborative model learning without the need to share raw data, but its communication links are vulnerable to interception, replay, and man-in-the-middle (MITM) attacks. The existing key exchange methods rely on computational hardness assumptions, which can be broken by post-quantum attackers. In this paper, a secure federated learning framework improved by Quantum Key Distribution (QKD) is proposed, which integrates BB84-like quantum key generation and authenticated encryption on a per-round basis, as well as Quantum Bit Error Rate (QBER)-assisted intrusion detection. A new cryptographic key is produced in each federated round, making it immune to replay attacks and allowing for detection of tampering. Theoretical calculations show that intercept-resend attacks lead to a minimum expected QBER of 25%, making it easier to detect statistically. Experimental results on the MNIST dataset show near-perfect detection rates for MITM and replay attacks, with QBER values increasing from about 1% (serving as a benign scenario) to about 26% in an attack scenario. Communication overhead is kept below 10%, with negligible computational latency compared to local training. The experiments show that the use of QKD-based key refresh improves FL communication security while still ensuring model convergence.
M. Kumari, Charvi Suri, Isha Suri· 2026 International Conferenc...· 0 citations
Quantum secret sharing (QSS) stands as one of the most promising components of quantum cryptography. Device-independent quantum secret sharing (DI-QSS) provides enhanced security by eliminating the need for device trust, yet its practical performance remains constrained by channel loss and noise. To overcome this limitation, this work innovatively integrates tripartite advantage distillation (AD) with an advanced random key generation basis strategy. This approach effectively improves the protocol’ s noise tolerance, reduces the global detection effciency threshold, and significantly extends the maximum secure communication distance. Numerical simulations demonstrate that, under ideal noisy channel conditions, the protocol’ s maximum secure distance increases from 0.82 km to 4.13 km, its global detection effciency threshold decreases from 93.42% to 80.23%, and the noise tolerance rises from 9.23% to 24.18%. This scheme significantly enhances the robustness of the protocol.
Yong-Hui Yang, Jian-Hong Shi, Hongwei Li et al.· Chinese Physics B· 0 citations
In quantum networks, Quantum Key Distribution (QKD) and the related protocols are distributive to ensure security for end users. Also, attack detection, analyzing security vulnerabilities and performance reduction over high traffic are more challenging which is encountered at multi-user communication end. Existing approaches does not effectually overcome the above given challenges. This research proposed a novel approaches that merges conventional quantum multiple access approaches, QKD and improved security protocols for dealing these issues. Here, a novel Resource-Efficient Quantum Key Distribution (RE-QKD) for establishing communication security among diverse nodes and adopts the conventional quantum multiple accesses. It intends to offer higher speed and scalability during the communication process. Then, security is optimized with RE-QKD that relies on Quantum Access Network to optimize the queries from various end-users. The proposed RE-QKD is proposed to provide security towards the computing attacks and preventing the eavesdropping attack. The proposed model work efficiently and gives promising outcomes with its performance metrics. The proposed RE-QKD model attains 95% detection attack, 97% communication complexity, distributive key rate of 600b/s, 99% computational overhead and 97% communication efficiency. The simulation outcomes shows the reduction in communication complexity up-to 45% and improved detection accuracy which is superior compared to prevailing approaches. The proposed model helps in scalable development and quantum network with better security.
N.Saranya, S. Sasirekha· Journal of Intelligent Decis...· 0 citations
In the rapidly evolving landscape of cybersecurity, traditional cryptographic systems are increasingly vulnerable to attacks, including brute-force, side-channel, man-in-the-middle, replay, and ransomware attacks, highlight the limitations of classical encryption techniques. Quantum cryptography leverages the no-cloning theorem and the properties of quantum states to establish fundamentally secure communication protocols with intrinsic eavesdropping detection capabilities. This security framework provides information-theoretic protection beyond the mathematical assumptions underlying conventional cryptographic systems. Quantum image security has evolved into two major paradigms: Quantum Key Distribution (QKD) and Quantum Secure Direct Communication (QSDC). Although recent surveys have reviewed both approaches chronologically, they have not systematically analysed their security thresholds The objective of this paper proposes a three-axis taxonomy of QSDC protocols, classifying them by quantum resource type, physical transmission channel, and device trust model. Furthermore, it presents a comparative performance analysis of QKD employing a hyperchaotic cipher over QSDC channels across seven quantum image representations, including FRQI, NEQR, GQIR, and MCQI. The analysis shows that QKD-seeded schemes achieve efficient key distribution, whereas pixel-level security remains dependent on cipher complexity. In contrast, QSDC provides end-to-end security governed by quantum mechanical principles; hyperentangled carriers achieve an eavesdropping detection probability of 0.875 compared with 0.5 for conventional two-step protocols, although communication throughput remains a limiting factor. Based on these findings, this review outlines future research directions, including QSDC-specific quantum repeaters for continental-scale deployment, hyperentangled carriers supporting up to 12 bits per photon pair compatible with NEQR’s 8-bit encoding, and machine-learning-assisted management of hybrid fiber–free-space quantum communication networks.
S. Deepika, N. Jeyanthi· Frontiers of Physics· 0 citations