Romanian Cyber Security Journal / Fall 2025, No. 2, Vol. 7

Quantum Networks and Cyber Security. A Simulation Case Study for Multi-Hop QKD Networks

Sorin SOVIANY, Cristina-Gabriela GHEORGHE, Maria GHEORGHE-MOISII

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Abstract

The paper addresses the Quantum Networks (QN) performance with Quantum Key Distribution (QKD) protocols. The focus is on networks with multi-hop paths (multiple QKD links with intermediate nodes). QKD emerged as a promising technology to ensure unconditioned communications security by exploiting the Quantum Computing (QC) and quantum principles. While the Point-to-Point (P2P) QKD links are well understood for several QKD protocols, the challenges concern the development of QN with multiple intermediate nodes and links. The deployment of quantum-secure communication systems over very large distances requires multi-hop QN. This paper presents a simulation-based case study for multi-hop QKD networks, focusing on the performance evaluation and the Cyber Security implications. The framework could be used to evaluate end-to-end key generation rates, latency, and resilience under various network topologies and link conditions. This methodology will allow to properly investigate how the network-level security policies can be integrated with QKD protocols to detect and mitigate both passive and active attacks. One could find out the trade-offs between hop count, security margins, and throughput, providing insights into the design of robust and scalable quantumsecure communication infrastructures. This study will support the research about the integration of the QKD with the classical network management, conventional security mechanisms and advanced Cyber defense strategies.

Keywords

Quantum networks, Quantum Key Distribution, Cyber Security, Multi-hop