Detection Challenges in BB84 Quantum Key Distribution under Random Number Generator Compromise and QBER Analysis

Abstract

This paper investigates the compromised random number generator (CRNG) attack, a novel quantum hacking threat to the quantum key distribution (QKD) that compromises random number generators (RNGs) that are crucial for basis selection and key generation. These vulnerabilities at the device level are a complement to previous research on implementation and side-channel attacks against hardware used in quantum communication, which take advantage of real-world flaws rather than the quantum channel itself. By preventing an increase in the quantum bit error rate (QBER), CRNG makes undetected key recovery possible, in contrast to quantum channel attacks. In addition to the above investigation, two methods are highlighted in the paper, namely, parametric tampering and reconstruction, which are supported by a mathematical model. 100% key recovery at insignificant QBER is possible with totally compromised RNGs, according to simulations. The simulations also show how the effect of a noisy quantum channel diminishes the similarity between the recreated key and the legitimate key. The findings highlight the necessity for protections beyond channel monitoring, such as quantum RNGs and hybrid key generation methods, and reveal weaknesses in traditional QKD components. © 2025 IEEE.