Hacking measurement-device-independent quantum key distribution
Feng-Yu Lu, Peng Ye, Ze-Hao Wang, Shuang Wang, Zhen‐Qiang Yin, Rong Wang, Xiaojuan Huang, Wei Chen, De‐Yong He, Guan‐Jie Fan‐Yuan, Guang‐Can Guo, Zheng‐Fu Han
Abstract
Decoy-state measurement-device-independent quantum key distribution (MDI-QKD) is regarded as one of the most promising protocols since it is physically immune to all fatal detection-side attacks. However, the loopholes in the source side still open side channels to eavesdroppers. Previous work has indicated that a system is insecure if its decoy-state modulation is inaccurate, but a practical method for Eve to exploit the inaccurate modulation is still absent. In this work, we propose a practical hacking method and provide a detailed theoretical analysis. Using our method, we experimentally hacked a MDI-QKD system and successfully obtained all final keys. By demonstrating the hacking experiment, we hope to bring attention to source-side security and provide inspiration for the development of protocols with better source-side security.