From key distribution to direct transmission: a comprehensive review of quantum image security via QKD and QSDC

QKD-Integrated Quantum Noise Stream Cipher: An Overview

Quantum Noise Stream Cipher (QNSC) has emerged as a physical-layer encryption technique that exploits quantum noise and non-orthogonal coherent-state modulation to secure optical communication. However, the security of QNSC relies exceedingly on the secrecy and freshness of its seed key. Quantum Key Distribution (QKD), on the other hand, provides information-theoretically secure key exchange rooted in the laws of quantum mechanics. The convergence of these two paradigms, i.e., integrated QKD-QNSC architectures, offers a compelling solution to each of their limitations. In such integrated systems, QKD continuously supplies and refreshes the secret seed key that governs QNSC modulation. Thus, governing a unified security framework that couples provably secure key establishment with high-speed quantum-enhanced physical-layer encryption. This work presents a comprehensive review of QNSC systems, examining their operating principles, security models under various attacks, and their integration with QKD systems. We analyze the security interplay between the key generation and encryption layers and survey experimental demonstrations and architectural progress toward practical deployment. Furthermore, we identify the open challenges and future research directions that must be addressed to realize fully integrated, quantum-secured optical communication networks at a practical scale.

A Comprehensive Review of Post-Quantum Cryptography and Its Implementation Challenges

Trust-aware hybrid QKD–PQC key management for quantum-safe communication networks

The security of today’s communication networks rests on public-key primitives—RSA and elliptic-curve Diffie–Hellman—that a large quantum computer would break with Shor’s algorithm, while the “harvest-now, decrypt-later” threat means traffic captured today is already at risk. Two defences exist but each is incomplete: quantum key distribution (QKD) offers information-theoretic security yet fails open under eavesdropping or channel loss, while post-quantum cryptography (PQC) is computationally secure and always available but lacks physical-layer guarantees. This paper presents a dual-layer, trust-aware key-management framework that uses BB84 QKD as the primary channel and a Ring-LWE/Kyber key-encapsulation mechanism as a quantum-safe fallback, governed by a controller monitoring the quantum bit-error rate (QBER) and a trust signal. When intercept-resend eavesdropping pushes the QBER past the 11% abort threshold—reached at roughly 40% interception—the controller falls back to PQC, holding secure availability at 100% where a QKD-only system degrades to 78.5%. The lattice fallback is cheap ( ≈ 0.47 m per operation) and Kyber-768 gives 192-bit quantum-safe security. Coupling the fallback and re-keying rate to a node trust score integrates physical-layer and computational security into one always-available, forward-secure key-management layer. To our knowledge, this is the first key-management framework in which a single network-layer trust signal jointly governs QKD/PQC layer selection and the re-keying cadence, unifying physical-layer eavesdropping detection, computational quantum-safety, and forward secrecy in one cross-layer policy.

Beyond encryption: post-quantum cryptography and the future of quantum-safe networks

This analysis demonstrates that while hybrid PQC-QKD models reduce long-term key compromise probabilities to near 0%, they introduce a 15% to 40% increase in bandwidth overhead during initial cryptographic handshakes during initial cryptographic handshakes.

Trends in Quantum Key Distribution Technologies: A Systematic Review of Protocols, Network Architectures, and Deployment Challenges

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.

Problems and prospects of building authentication methods in quantum key distribution channels

The paper addresses entity authentication in quantum key distribution (QKD) systems as a decisive condition of their practical security. It is shown that the information-theoretic security of quantum key agreement does not eliminate the need to authenticate the communicating parties: an unauthenticated classical channel leaves the system exposed to the man-in-the-middle attack, since the eavesdropper can run independent QKD instances with each party and reconcile two keys under full control. Existing authentication methods are analysed and classified by the underlying cryptographic primitive: symmetric schemes based on Wegman–Carter universal hashing, pre-shared and fixed keys, public-key infrastructure, two-way authentication, quantum entity/identity authentication, and zero-knowledge proofs. For each class the operating principle, advantages and limitations are determined, with emphasis on key management, scalability and trust distribution. It is established that symmetric and quantum-layer methods rely on pre-shared secrets with a quadratic growth of key material, public-key infrastructure introduces a single trust bottleneck and quantum-vulnerable primitives, while existing zero-knowledge authentication schemes are quantum and bound to the physical layer or solve network properties other than identity. A comparative analysis reveals an unresolved scientific gap: the absence of a scalable entity-authentication method that simultaneously provides non-disclosure of the secret, quantum resistance, sub-quadratic scalability and minimisation of trust assumptions. On this basis, a prospective research direction is substantiated – the construction of entity-authentication methods based on post-quantum zero-knowledge proofs operating over the classical control plane of scalable QKD networks. The requirements for such a method are formulated, and its compatibility with formal QKD security proofs is discussed.