Unveiling Bb84 Vulnerabilities: A Quantum Key Distribution Simulation Library
Ignacio Astaburuaga, Suman Rath, Shamik Sengupta · 2025
The US National Security Agency (NSA) has emphasized that Quantum Key Distribution (QKD) protocols have technical limitations making them unfeasible for national security systems. However, several researchers have debated against this narrative stating their robustness. This disagreement makes it essential for more researchers and pen-testers to study QKD and determine its robustness, performance efficiency, and/or vulnerabilities. However, simulating QKD protocols often needs an in-depth domain knowledge of both cryptography and quantum physics making it difficult for security researchers to understand and cross-examine them. To alleviate the problem, this paper implements the standard BB84 QKD protocol, develops an easily reconfigurable simulator library, and showcases how it can be used to uncover the protocol's vulnerabilities. Using the simulator, we uncover and demonstrate a major vulnerability in the BB84 protocol via which persistent eavesdroppers can evade generic detection under certain probabilistic conditions and launch denial-of-service attacks. The paper also demonstrates this vulnerability in real-time via the simulator showcasing its robustness and capabilities.