Information reconciliation (IR) for continuous variable quantum key distribution (QKD) over free space optics (FSO) channel

Fred Daneshgaran, Marina Mondin, Shlomi Arnon, Francesco Di Stasio, Judy Kupferman

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Quantum Key Distribution (QKD) is a communication method which exchanges secret keys using cryptographic protocols involving elements from quantum science. Continuous Variable (CV) QKD is a method to implement key exchange using sampling of Gaussian signals. Reconciliation in CV-QKD is fundamentally realized via coding of the Alice or Bob binary labels of the Gaussian samples using either one-way or interactive communications between the parties, Alice and Bob, over a public authenticated channel. We assume that the communication is performed through an Optical Wireless (OW) or Free Space Optics (FSO) channel. In that case the received signal suffers from stochastic fading due to pointing jitter or atmospheric turbulence. As a result of the channel fading and noise Alice and Bob Gaussian samples will not match. Information Reconciliation (IR) is the phase of the CV-QKD protocol that makes sure that Alice and Bob agree on a common and identical labeling of their samples, i.e. agree on a common stream of bits that we denote as and quot;reconciled key." The information reconciliation in CV-QKD could be done by one-way or two-way channel coding to correct the actual labels so that they do match. To do so Bob generates a sequence of parity bits using a systematic code. These bits are sent to Alice over an authenticated public channel. Alice then uses her own sequence of labels she obtains after quantization with the redundancy provided by Bob to recover Bob's binary sequence. In this work we analyze the problem of information reconciliation for continuous variable quantum key distribution over a free space optics channel.

Original languageEnglish
Title of host publicationFree-Space Laser Communications XXXI
EditorsDon M. Boroson, Hamid Hemmati
ISBN (Electronic)9781510624627
StatePublished - 1 Jan 2019
EventFree-Space Laser Communications XXXI 2019 - San Francisco, United States
Duration: 4 Feb 20196 Feb 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering


ConferenceFree-Space Laser Communications XXXI 2019
Country/TerritoryUnited States
CitySan Francisco


  • CV-QKD
  • FSO
  • IR
  • free space optics channel
  • information reconciliation.

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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