QKDNetSim+: Improvement of the Quantum Network Simulator for NS-3

TL;DR

The paper addresses the need for realistic QKD network simulation by evaluating the NS-3 based QKDNetSim and identifying critical shortcomings in key management and encryption. It proposes an enhanced QKDNetSim architecture that preserves the original module structure but introduces a dedicated QKD Random Generator, a two-tier Key Storage system (Raw material storage and Key Database), and a functioning encryption pipeline with a QKDHeader. Key contributions include the ability to generate real or QRNG-derived key material, synchronized key reservations across communicating nodes, and proper encryption/authentication of packets, all integrated into NS-3. The enhanced simulator offers more faithful emulation of QKD networks, enabling researchers to study key synchronization, material management, and the impact of realistic randomness on network performance, with practical QRNG integration like Quantis at up to about 4 Mb/s.

Abstract

The first Quantum Key Distribution (QKD) networks are currently being deployed, but the implementation cost is still prohibitive for most researchers. As such, there is a need for realistic QKD network simulators. The \textit{QKDNetSim} module for the network simulator NS-3 focuses on the representation of packets and the management of key material in a QKD network at the application layer. Although QKDNetSim's representation of a QKD network is insightful, some its components lack the depth that would allow the simulator to faithfully represent the behaviour of a real quantum network. In this work, we analyse QKDNetSim's architecture to identify its limitations, and we present an enhanced version of QKDNetSim in which some of its components have been modified to provide a more realistic simulation environment.

Figures (5)

• Figure 1: Diagram of a QKD communication.
• Figure 2: Architecture of QKDNetSim.
• Figure 3: Packet containing key material sent by Charging Application.
• Figure 4: Amount of available key material inside the Key Buffer throughout the simulation.
• Figure 5: Contents of an encrypted message sent by the Send Application.