A Digital Twin Approach to Quantum Key Distribution Under Eavesdropping
Angela Diaz-Bricio, Blanca López, Iván Vidal, Francisco Valera · 2025
Quantum Key Distribution (QKD) enables secure key exchange by leveraging quantum mechanics to provide theoretically unbreakable security. However, practical deployment of QKD networks is limited due to high costs, lack of interoperability of existing commercial products, and complex physical requirements. To address these challenges, digital twins of QKD networks provide an accessible and adaptable solution for testing and experimentation in emulated environments. This work presents the design of a digital twin model that emulates a QKD network under eavesdropping, allowing for realistic analysis of network behavior in the presence of security threats. As an initial stage, an emulation service of a QKD link with an eavesdropper has been implemented using the NetSquid simulator, offering a practical tool for testing QKD security. This model offers a versatile framework that can be adapted for use in different platforms and applications, providing not only a means to understand this threat and assess countermeasure effectiveness but also a method to analyze how attacks impact exchanged keys and the timing of key distribution.