Pan Jianwei and Chen Tengyun of the University of Science and Technology of China cooperated with Ma Xiongfeng of Tsinghua University to achieve pattern-matching quantum key distribution experimentally for the first time. The relevant research results were recently published in Physical Review Letters.
Schematic diagram of pattern-matched quantum key distribution protocol Courtesy of China University of Science and Technology
Quantum key distribution is based on the basic principles of quantum mechanics, which can realize theoretically unconditionally secure confidential communication, so it has been a research hotspot in academia in recent decades. Pattern-matched quantum key distribution protocol (MP-QKD) is a new measurement device-independent quantum key distribution protocol proposed by Ma Xiongfeng Research Group of Tsinghua University in 2022, which requires both parties to first encode the information in a single optical mode, based on the detection response results, the communication parties pair according to certain rules, and then perform post-processing operations such as base vector comparison and parameter estimation according to the pairing situation to generate the final security key. Compared with the original measurement equipment-independent protocol, MP-QKD can use more detection events for code formation, which can greatly improve the code formation rate; Compared with the two-field quantum key distribution protocol and phase matching protocol, MP-QKD does not require complex laser lock-in technology, which saves cost and reduces practical application difficulty, and has better anti-interference ability against environmental noise.
Based on the pattern-matching quantum key distribution protocol proposed by Ma Xiongfeng’s research group of Tsinghua University, the research group of Pan Jianwei and Chen Tengyun accurately estimated the frequency difference of two independent lasers for parameter estimation by using the data post-processing method of great likelihood estimation, and combined with the high-efficiency single-photon detector developed by You Lixing team of the Shanghai Institute of Microsystems of the Chinese Academy of Sciences, the safety coding of laboratory standard optical fibers of 100 km, 200 km, 300 km and ultra-low loss fiber of 400 km was realized. Compared with the previous original measurement equipment-independent quantum cryptography experiment, the code rate has been significantly improved, and the code rate has increased by 3 orders of magnitude compared with the previous experiment at a distance of 300 km and 400 km.
The research results show that pattern-matched quantum key distribution can achieve long-distance safe coding and high code rate in metro distance without laser frequency locking, which greatly reduces the difficulty of protocol implementation and is of great significance to the construction of quantum communication networks in the future. (Source: Wang Min, China Science News)
Related paper information:https://doi.org/10.1103/PhysRevLett.130.030801