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Quantum key distribution with imperfect devices

Research Project

Project/Area Number 18K13469
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 13010:Mathematical physics and fundamental theory of condensed matter physics-related
Research InstitutionThe University of Tokyo

Principal Investigator

Sasaki Toshihiko  東京大学, 大学院工学系研究科(工学部), 講師 (80734350)

Project Period (FY) 2018-04-01 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2021: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Keywords量子情報理論 / 量子鍵配送 / 量子暗号 / 装置不完全性 / 量子情報
Outline of Final Research Achievements

The purpose of this research project is to extend the device model of quantum key distribution to be more realistic without sacrificing performance as much as possible, and to guarantee security using data that can be confirmed by experiments. There are various studies on extending the device model of quantum key distribution, but most of them consider only the asymptotic performance when the experimental time is infinite, which simplifies the analysis. This project is unique in that it analyzed the case of finite experimental time.
The subjects in this project are how to rigorously test light sources, how to avoid the negative effects of substituting the devices with cheaper ones, how to perform quantum key distribution using photodetectors, which is cheaper than photon detectors, and how to develop numerical methods that can automatically deal with various device imperfections.

Academic Significance and Societal Importance of the Research Achievements

量子鍵配送は遠隔2者間で安全な乱数列を共有する手法であり、これを用いることで長期的に安全な秘密通信が可能になる。この手法は実際に製品にもなり、社会に導入されようとしている。実際の装置の安全性を示すためには、理想化された状況だけでなく、現実に即したモデルを考える必要があるが。本研究課題では、現実的な制約のもとで安全性を示すための新たな手法を開発することで、理論と現実のギャップを縮め、量子鍵配送を安価に実現することに貢献した。

Report

(5 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (15 results)

All 2022 2021 2020 2019 2018 Other

All Journal Article (6 results) (of which Peer Reviewed: 6 results,  Open Access: 3 results) Presentation (8 results) (of which Int'l Joint Research: 3 results,  Invited: 4 results) Remarks (1 results)

  • [Journal Article] Finite-size security of continuous-variable quantum key distribution with digital signal processing2021

    • Author(s)
      Matsuura Takaya、Maeda Kento、Sasaki Toshihiko、Koashi Masato
    • Journal Title

      Nature Communications

      Volume: 12 Issue: 1 Pages: 252-252

    • DOI

      10.1038/s41467-020-19916-1

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Refined security proof of the round-robin differential-phase-shift quantum key distribution and its improved performance in the finite-sized case2019

    • Author(s)
      Matsuura Takaya、Sasaki Toshihiko、Koashi Masato
    • Journal Title

      Physical Review A

      Volume: 99 Issue: 4 Pages: 042303-042303

    • DOI

      10.1103/physreva.99.042303

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Blind quantum computation with a heralded single-photon source2019

    • Author(s)
      Nagao Kurumiko、Horikiri Tomoyuki、Sasaki Toshihiko
    • Journal Title

      Physical Review A

      Volume: 99 Issue: 4 Pages: 042324-042324

    • DOI

      10.1103/physreva.99.042324

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Repeaterless quantum key distribution with efficient finite-key analysis overcoming the rate-distance limit2019

    • Author(s)
      Maeda Kento、Sasaki Toshihiko、Koashi Masato
    • Journal Title

      Nature Communications

      Volume: 10 Issue: 1 Pages: 3140-3140

    • DOI

      10.1038/s41467-019-11008-z

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Quantum key distribution with simply characterized light sources2019

    • Author(s)
      Mizutani Akihiro、Sasaki Toshihiko、Takeuchi Yuki、Tamaki Kiyoshi、Koashi Masato
    • Journal Title

      npj Quantum Information

      Volume: 5 Issue: 1 Pages: 87-87

    • DOI

      10.1038/s41534-019-0194-3

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Rigorous characterization method for photon-number statistics2019

    • Author(s)
      Kumazawa Masahiro、Sasaki Toshihiko、Koashi Masato
    • Journal Title

      Optics Express

      Volume: 27 Issue: 4 Pages: 5297-5297

    • DOI

      10.1364/oe.27.005297

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] 量子暗号通信の安全性2022

    • Author(s)
      佐々木寿彦
    • Organizer
      日本銀行金融研究所 情報技術研究センター 情報セキュリティ・セミナー
    • Related Report
      2021 Annual Research Report
    • Invited
  • [Presentation] 量子鍵配送の有限長安全性証明手法の現状について2021

    • Author(s)
      佐々木寿彦
    • Organizer
      第45回量子情報技術研究会 (QIT45)
    • Related Report
      2021 Annual Research Report
    • Invited
  • [Presentation] 量子鍵配送の現状と理論的課題について2021

    • Author(s)
      佐々木寿彦
    • Organizer
      第3回量子ソフトウェア研究発表会
    • Related Report
      2021 Annual Research Report
  • [Presentation] Estimation protocol: its definition and usage in security proofs2020

    • Author(s)
      Toshihiko Sasaki
    • Organizer
      Security proofs in QKD Workshop
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research
  • [Presentation] 量子鍵配送の安全性が証明できる状況について2020

    • Author(s)
      佐々木寿彦
    • Organizer
      量子論の諸問題と今後の発展
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Security proof of QKD as a combination of classical arguments: Based on the twin-field-type QKD2019

    • Author(s)
      Toshihiko Sasaki
    • Organizer
      Quantum computation, post-quantum cryptography and quantum codes
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Rigorous calibration method for photon-number statistics2018

    • Author(s)
      Toshihiko Sasaki
    • Organizer
      CQIS2018
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] Feedforward attack in decoy-state quantum key distribution2018

    • Author(s)
      Toshihiko Sasaki
    • Organizer
      QCrypt2018
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Remarks] 量子暗号の到達距離を2倍に―新しい推定手法で盗聴監視の困難を解決―:物理工学専攻 小芦雅斗教授ら

    • URL

      https://www.t.u-tokyo.ac.jp/soe/press/setnws_201907181631518423964178.html

    • Related Report
      2019 Research-status Report

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Published: 2018-04-23   Modified: 2023-01-30  

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