This preprint presents the NEPO Project, a foundational proposal for a modular, hybrid quantum–classical communication infrastructure designed to remain viable under long-term technological uncertainty. Rather than treating quantum security as a standalone cryptographic upgrade, the work frames secure communication as a system-level constraint involving hardware architecture, deterministic identity, memory partitioning, routing, and verification as co-dependent primitives. The proposed architecture introduces a layered, two-plane network model in which quantum key distribution functions as a root of trust, while classical computation and localized agents provide scalability, adaptability, and fault tolerance. Devices are treated as accountable participants within a partitioned mesh, independent of ownership or trust assumptions. Mathematical formalisms, physical signal models, and material-specific optimizations are intentionally deferred to supplementary work in order to preserve architectural clarity and longevity. This document is intended as an architectural and conceptual foundation for future research in distributed systems, secure networking, and quantum-aware infrastructure design.
This preprint presents the NEPO Project, a foundational proposal for a modular, hybrid quantum–classical communication infrastructure designed to remain viable under long-term technological uncertainty. Rather than treating quantum security as a standalone cryptographic upgrade, the work frames secure communication as a system-level constraint involving hardware architecture, deterministic identity, memory partitioning, routing, and verification as co-dependent primitives. The proposed architecture introduces a layered, two-plane network model in which quantum key distribution functions as a root of trust, while classical computation and localized agents provide scalability, adaptability, and fault tolerance. Devices are treated as accountable participants within a partitioned mesh, independent of ownership or trust assumptions. Mathematical formalisms, physical signal models, and material-specific optimizations are intentionally deferred to supplementary work in order to preserve architectural clarity and longevity. This document is intended as an architectural and conceptual foundation for future research in distributed systems, secure networking, and quantum-aware infrastructure design.
Quantum Key Distribution (QKD) has progressed from a theoretical cryptographic concept to an emerging secure communication infrastructure technology. While early work focused on protocol security and physical-layer feasibility, current research increasingly addresses scalable network deployment, hardware acceleration, and integration with classical communication systems. As QKD expands from point-to-point links to metropolitan, backbone, and hybrid satellite–terrestrial networks, new engineering challenges arise in topology design, entropy generation, real-time key distillation, and multi-vendor interoperability. This survey provides an infrastructure-oriented review of QKD networks, examining architectural models, quantum randomness as a root of trust, FPGA and system-on-chip (SoC) based acceleration techniques, and programmable control-plane integration. Key management system architectures and standardized interfaces are analyzed to highlight their roles in enabling scalable, interoperable deployments. The paper also synthesizes major standardization efforts and deployment initiatives shaping carrier-grade QKD infrastructures. Finally, open engineering challenges, including scalability, control-plane integration, certification harmonization, and hybridization with post-quantum cryptography, are identified, positioning QKD as a foundational component of next-generation secure communication systems.
Large-scale quantum computers threaten the public-key cryptographic foundations underpinning today's network security infrastructures. While significant progress has been made in standardizing post-quantum cryptographic (PQC) primitives and adapting individual protocols such as TLS and SSH, far less attention has been paid to the broader architectural consequences of the post-quantum transition for networked systems. In particular, many real-world deployments such as mobile networks, industrial control systems, IoT environments, and regulated infrastructures cannot assume the universal availability, deployability, or desirability of PQ public-key infrastructures. This paper presents the first comprehensive systematization of PQ-resistant network architectures, focusing on key distribution and management as a system-level design problem rather than a protocol-local substitution. We introduce a unified taxonomy spanning cryptographic foundations (symmetric-only, PQ-PKI, hybrid, and information-theoretic multi-path), key-distribution architectures (centralized, hierarchical, replicated, threshold, MPC-backed, and serverless), trust and threat models, key-management lifecycle, and deployment environments. Using this framework, we analyze the security, scalability, and operational trade-offs of a wide range of architectures under realistic PQ adversary assumptions, including harvest-now, decrypt-later attacks and partial infrastructure compromise. Our study highlights fundamental gaps in existing approaches, clarifies when PQ-PKI is necessary or avoidable, and identifies promising research directions for building cryptographically agile, quantum-resilient network infrastructures.
In the field of Internet service evolution, classical and quantum paradigms are often seen as distinct and separate research areas. Typically, the classical Internet is perceived as a foundational communications infrastructure for the emerging quantum Internet, mainly providing essential services such as synchronization, signaling, control, and feedback. Current quantum Internet research requires a radical transformation of physical layer devices, often leading to the obsolescence of existing classical infrastructures. To address this challenge, in this work we introduce a new hybrid approach for the future development of the quantum Internet. Specifically, we will delve into various mechanisms and technologies that facilitate the integration of quantum networks with future 6G networks. Our goal is to develop a complete model for a hybrid quantum-classical Internet designed for future generation 6G in order to jointly and efficiently support both quantum and classical communications. In particular, we explore an innovative hybrid datalink layer architecture that is critical for effectively managing the diverse nature of quantum and classical data traffic and security. The main advantage of our model lies in the integration of new quantum hardware at the physical layer while leveraging existing advanced classical infrastructure. Our model is proposed as a step forward in the harmonization of quantum and classical Internet technologies, paving the way for a secure and fast future 6G architecture.
Quantum computing is a new discipline that uses the ideas of quantum physics to do calculations that are not possible with conventional computers. Quantum bits, called qubits, could exist in superposition states, making them suitable for parallel processing in contrast to traditional bits. When it comes to addressing complex challenges like proof simulation, optimization, and cryptography, quantum entanglement and quantum interference provide exponential improvements. This survey focuses on recent advances in entanglement routing, quantum key distribution (QKD), and qubit management for short- and long-distance quantum communication. It studies optimization approaches such as integer programming, reinforcement learning, and collaborative methods, evaluating their efficacy in terms of throughput, scalability, and fairness. Despite improvements, challenges remain in dynamic network adaptation, resource limits, and error correction. Addressing these difficulties necessitates the creation of hybrid quantum–classical algorithms for efficient resource allocation, hardware-aware designs to improve real-world deployment, and fault-tolerant architecture. Therefore, this survey suggests that future research focus on integrating quantum networks with existing classical infrastructure to improve security, dependability, and mainstream acceptance. This connection has significance for applications that require secure communication, financial transactions, and critical infrastructure protection.
Abstract: This study advances a unifying systems perspective on quantum-safe network security by synthesizing recent progress in quantum cryptography with practical integration patterns across carrier-grade infrastructures. Concept analysis distinguishes the roles of quantum key distribution (QKD), device-independent variants, quantum authentication, and post-quantum cryptography (PQC) within zero-trust architectures. Building on this, a layered framework—spanning physical/entanglement resources, key management, crypto-agility, control plane orchestration, and policy/compliance—is articulated to support end-to-end, composable guarantees. The problem addressed is the realization of verifiable, quantum-resilient security under operational constraints involving latency, key-rate variability, and heterogeneous trust assumptions. Methodology combines a structured literature synthesis with formal composability mapping to universal composability principles, adversarial threat modeling for quantum-enabled attackers, and testbed/simulation evaluation of hybrid QKD–PQC pipelines across L2–L3 segments and 5G/6G backhaul scenarios. Key results indicate that (i) selective QKD deployment on high-value links coupled with PQC at endpoints enhances resilience while preserving crypto-agility; (ii) automated key-lifecycle orchestration reduces exposure windows; and (iii) device-independent assurances strengthen guarantees where trust relaxation is necessary. The impact is a deployment-ready reference architecture, measurable integration metrics, and guidance aligned with emerging standards for critical infrastructure and national networks. The implications extend to procurement, compliance, and roadmap planning for quantum-era network security. Keywords: quantum-safe cryptography, quantum key distribution (QKD), post-quantum cryptography (PQC), hybrid QKD–PQC, composable security, device-independent QKD, zero-trust networks, key management and orchestration, 5G/6G backhaul, network security architecture, standards and interoperability
The rapid advancement of quantum computing threatens the security foundations of classical public-key cryptographic systems such as RSA and Elliptic Curve Cryptography (ECC), which underpin cloud and edge infrastructures. With scalable quantum algorithms capable of breaking widely deployed cryptographic primitives, organizations must transition toward quantum-resilient security models. This paper proposes a comprehensive Quantum-Resilient Cryptographic Architecture (QRCA) designed specifically for cloud and edge computing environments. The framework integrates post-quantum cryptographic (PQC) algorithms, hybrid key exchange protocols, zero-trust principles, and hardware-assisted secure enclaves. We present a layered security model that balances computational overhead, latency constraints, and scalability requirements in distributed systems. Experimental simulations evaluate performance metrics including encryption latency, key exchange overhead, and throughput across cloud data centres and edge nodes. Results indicate that hybrid PQC deployments achieve strong quantum resilience with manageable performance trade-offs. The proposed architecture offers a practical migration pathway for organizations seeking future-proof cryptographic security in distributed computing ecosystems.