Title: Noise Analysis of Simultaneous Quantum Key Distribution and Classical Communication Scheme Using a True Local Oscillator

Abstract

Recently, we proposed a simultaneous quantum and classical communication (SQCC) protocol where random numbers for quantum key distribution and bits for classical communication are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Such a scheme could be appealing in practice since a single coherent communication system can be used for multiple purposes. However, previous studies show that the SQCC protocol can tolerate only very small phase noise. This makes it incompatible with the coherent communication scheme using a true local oscillator (LO), which presents a relatively high phase noise due to the fact that the signal and the LO are generated from two independent lasers. We improve the phase noise tolerance of the SQCC scheme using a true LO by adopting a refined noise model where phase noises originating from different sources are treated differently: on the one hand, phase noise associated with the coherent receiver may be regarded as trusted noise since the detector can be calibrated locally and the photon statistics of the detected signals can be determined from the measurement results; on the other hand, phase noise due to the instability of fiber interferometers may be regarded as untrusted noise sincemore » its randomness (from the adversary’s point of view) is hard to justify. Simulation results show the tolerable phase noise in this refined noise model is significantly higher than that in the previous study, where all of the phase noises are assumed to be untrusted. In conclusion, we conduct an experiment to show that the required phase stability can be achieved in a coherent communication system using a true LO.« less

Authors:

Qi, Bing; Lim, Charles Ci Wen

Publication Date:

Mon May 07 00:00:00 EDT 2018

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1436216

Alternate Identifier(s):

OSTI ID: 1436955

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Published Article

Journal Name:

Physical Review Applied

Additional Journal Information:

Journal Name: Physical Review Applied Journal Volume: 9 Journal Issue: 5; Journal ID: ISSN 2331-7019

Publisher:

American Physical Society

Country of Publication:

United States

Language:

English

Subject:

97 MATHEMATICS AND COMPUTING