Improving the performance of practical decoy-state quantum key distribution with advantage distillation technology

• Published in: Communications physics Vol. 5; no. 1; pp. 1 - 8
• Main Authors: Li, Hong-Wei, Zhang, Chun-Mei, Jiang, Mu-Sheng, Cai, Qing-Yu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.03.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1075/187; 639/766/483/481; Cryptography; Distillation; Information theory; Performance enhancement; Physics; Physics and Astronomy; Protocol; Quantum cryptography; Technology assessment
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-022-00831-4

Quantum key distribution (QKD) provides a promising solution for sharing information-theoretic secret keys between two remote legitimate parties. To improve the maximal transmission distance and the maximal error rate tolerance, we apply the advantage distillation technology to analyze the security of practical decoy-state QKD systems. Based on the practical experimental parameters, the device-dependent QKD protocols and the measurement-device-independent QKD protocols have been respectively analyzed, and our analysis results demonstrate that the advantage distillation technology can significantly improve the performance of various QKD protocols. In the four-state and six-state device-dependent QKD protocols, we prove that the maximal transmission distance can be improved from 142 km to 180 km and from 146 km to 187 km respectively. In the four-state and six-state measurement-device-independent QKD protocols, we prove that the maximal transmission distance can be improved from 195 km to 273 km and from 200 km to 282 km respectively. Advantage distillation technology increases the collection between raw keys in quantum key distribution systems. Combining a decoy state method with advantage distillation technology, the authors demonstrate improved maximal transmission distance and tolerable background error rates.