Affordable Access

Access to the full text

High efficiency postprocessing for continuous-variable quantum key distribution: using all raw keys for parameter estimation and key extraction

Authors
  • Wang, Xiangyu1
  • Zhang, Yichen1
  • Yu, Song1
  • Guo, Hong2
  • 1 Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communications, Beijing, 100876, China , Beijing (China)
  • 2 Peking University, State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics Engineering and Computer Science, Center for Quantum Information Technology, Center for Computational Science and Engineering, Beijing, 100871, China , Beijing (China)
Type
Published Article
Journal
Quantum Information Processing
Publisher
Springer-Verlag
Publication Date
Jul 17, 2019
Volume
18
Issue
9
Identifiers
DOI: 10.1007/s11128-019-2381-8
Source
Springer Nature
Keywords
License
Yellow

Abstract

High efficiency postprocessing of continuous-variable quantum key distribution (CV-QKD) system has a significant impact on the secret key rate and transmission distance of the system. For a quantum channel with unknown prior characteristics, we have to sacrifice part (typically half) of the raw keys to estimate the channel parameters, which is used to assist in error correction and estimate the secret key rate. This introduces a trade-off between the secret key rate and the accuracy of parameter estimation when considering the finite-size effect. In this paper, we propose a high efficiency postprocessing method which uses all the raw keys for both parameter estimation and key extraction. The correcting party uses the extra data (used for phase compensation and synchronization etc.) to roughly estimate the quantum channel parameters, or she can use the results of the last block, then she selects a suitable code to correct the errors between them, finally she recovers the raw keys of the other side by a reverse mapping function after the success of error correction. Then, she uses all the raw keys of both sides for parameter estimation. We show that this method improves the accuracy of parameter estimation and the secret key rate of CV-QKD system.

Report this publication

Statistics

Seen <100 times