Yichen Liu

Quantum key distribution (QKD) protocol has been proven to be informationally-theoretical security. Unfortunately, due to device imperfections in practice, QKD systems have exposed various vulnerabilities that are exploited by an eavesdropper to conduct quantum hackings, such as laser-seeding attacks, blinding attacks, etc. Most of these attacks currently remain only at the stage of possibility verification or white-box testing. In this paper, we propose and implemented plug-and-play attack on a QKD system as a black box, whose interface and access for the public are the only known information. Through this attack, we actively modified the gate positions and synchronization parameters of the QKD system during the calibration procedure, allowing the attack operate during the whole lifetime of the system running without being noticed. Furthermore, the implemented hacking system only connects to the quantum channel but has no access to the inside of QKD engine, which takes minutes to optimize the hacking parameters to start the eavesdropping. This work illustrates Eve's capability to successfully eavesdrop on keys from QKD systems under current conditions in a more intuitive and concrete way.