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Understanding the Network Structure and Dynamics of Cryptoasset's Transactions at a Global Scale

Research Project

Project/Area Number 19K22032
Research Category

Grant-in-Aid for Challenging Research (Exploratory)

Allocation TypeMulti-year Fund
Review Section Medium-sized Section 25:Social systems engineering, safety engineering, disaster prevention engineering, and related fields
Research InstitutionUniversity of Hyogo

Principal Investigator

Fujiwara Yoshi  兵庫県立大学, 情報科学研究科, 教授 (50358892)

Co-Investigator(Kenkyū-buntansha) 日高 義将  国立研究開発法人理化学研究所, 仁科加速器科学研究センター, 専任研究員 (00425604)
初田 哲男  国立研究開発法人理化学研究所, 数理創造プログラム, プログラムディレクター (20192700)
井上 寛康  兵庫県立大学, シミュレーション学研究科, 准教授 (60418499)
土居 孝寛  大阪大学, 核物理研究センター, 特任助教(常勤) (50804910)
Project Period (FY) 2019-06-28 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2021: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2020: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2019: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Keywords暗号資産 / ブロックチェーン / 決済システム / 複雑ネットワーク / 代数的トポロジー / ビットコイン / コホモロジー
Outline of Research at the Start

ビットコインを代表とする暗号通貨を対象として、それら決済および取引価格の大規模なデータを収集して、その詳細な情報に基づいて、ユーザー間の通貨流通の全体像、すなわち決済ネットワークの構造とその時間的な変化、ならびに取引価格のダイナミクスを解明する。これまでは通貨の流れを把握するということさえ、そのデータの入手困難さのため、ほぼ不可能であった。この萌芽的な研究は、暗号通貨の大規模データベース構築のための情報科学ならびに計算科学、決済の膨大な関係性を明らかにする複雑ネットワーク科学、特に通貨の流れの新しい数理的な解析手法などを用いて、決済ネットワークの構造とダイナミクスを解明する。

Outline of Final Research Achievements

This study concerns about transactions recorded in the largest cryptoasset of Bitcoin's blockchain. Based on the estimation of users from wallets (addresses) in the blockchain, we define a crypto flow network comprising users as nodes and transactions as edges, and analyzed the network structure and its temporal change by using complex network analysis.
As a result, by using an algebraic topology of Hodge decompostiion, we clarfied each user's location related to demand and supply of the crypto and the network structure, regarding the upstream/downstream flow and the strongly connected component. In addition, by applying a machine learning method of non-negative matrix factorization in the framework of Bayesian estimation, we revealed big players' activities in the principal components of crypto flow.

Academic Significance and Societal Importance of the Research Achievements

通貨の本質は信用取引を記録するための帳簿(ledger)である。すべての経済活動は信用(credit)を基盤とするから、通貨の流れと取引価格の決定についての研究は、信用取引としての決済システムという社会基盤として極めて重要である。これまで、通貨の流れを把握するということさえ、そのデータの入手困難さのため、ほぼ不可能であった。
本研究は、ビットコインを代表とする暗号通貨を対象として、それら決済および取引価格の大規模なデータを収集して、その詳細な情報に基づいて、ユーザー間の通貨流通の全体像、すなわち決済ネットワークの構造とその時間的な変化、ならびに取引価格のダイナミクスを解明する研究を行った。

Report

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

    (16 results)

All 2021 2020 2019

All Journal Article (8 results) (of which Peer Reviewed: 7 results,  Open Access: 6 results) Presentation (7 results) (of which Int'l Joint Research: 7 results) Funded Workshop (1 results)

  • [Journal Article] Bitcoin’s Crypto Flow Network2021

    • Author(s)
      Yoshi Fujiwara, Rubayiat Islam
    • Journal Title

      JPS Conference Proceedings

      Volume: 36 Pages: 11002-11002

    • DOI

      10.7566/jpscp.36.011002

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Statistical Property of Interfirm Trading Network Based on Multi-Agent Based Model2021

    • Author(s)
      Hidaka Yoshimasa、Ohkoda Shunsuke、Nitta Takeru、Doi Takahiro、Yamaguchi Yasuhiro、Yanaoka Masaki
    • Journal Title

      JPS Conference Proceedings

      Volume: 36 Pages: 011009-011009

    • DOI

      10.7566/jpscp.36.011009

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Analysis of Business-to-Business Transactions for Corporate Growth Forecast2021

    • Author(s)
      Doi Takahiro、Ohkoda Shunsuke、Nitta Takeru、Hidaka Yoshimasa、Yamaguchi Yasuhiro、Yanaoka Masaki
    • Journal Title

      JPS Conference Proceedings

      Volume: 36 Pages: 011010-011010

    • DOI

      10.7566/jpscp.36.011010

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Unfolding identity of financial institutions in bitcoin blockchain by weekly pattern of network flows2021

    • Author(s)
      Rubayiat Islam, Yoshi Fujiwara, Shinya Kawata, Hiwon Yoon
    • Journal Title

      Evolutionary and Institutional Economics Review

      Volume: 18 Issue: 1 Pages: 131-157

    • DOI

      10.1007/s40844-020-00184-z

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Hodge Decomposition of Bitcoin Money Flow2020

    • Author(s)
      Yoshi Fujiwara, Rubayiat Islam
    • Journal Title

      Advanced Studies of Financial Technologies and Cryptocurrency Markets

      Volume: NA Pages: 117-137

    • DOI

      10.1007/978-981-15-4498-9_7

    • ISBN
      9789811544972, 9789811544989
    • Related Report
      2020 Research-status Report
  • [Journal Article] Interindustry linkages of prices---Analysis of Japan's deflation2020

    • Author(s)
      Yuichi Kichikawa, Hiroshi Iyetomi, Hideaki Aoyama, Yoshi Fujiwara, Hiroshi Yoshikawa
    • Journal Title

      PLoS ONE

      Volume: 15 Issue: 2 Pages: 1-26

    • DOI

      10.1371/journal.pone.0228026

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Local bow-tie structure of the web2019

    • Author(s)
      Yuji Fujita, Yuichi Kichikawa, Yoshi Fujiwara, Wataru Souma, and Hiroshi Iyetomi
    • Journal Title

      Applied Network Science

      Volume: 4 Issue: 1 Pages: 15-15

    • DOI

      10.1007/s41109-019-0127-2

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Community structure based on circular flow in a large-scale transaction network2019

    • Author(s)
      Y. Kichikawa, H. Iyetomi, T. Iino, and H. Inoue
    • Journal Title

      Applied Network Science

      Volume: 92 Issue: 1 Pages: 92-92

    • DOI

      10.1007/s41109-019-0202-8

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Presentation] Cryptoasset Networks: Big Players and Flows in Bitcoin and XRP2021

    • Author(s)
      Hideaki Aoyama, Yoshi Fujiwara
    • Organizer
      10th International Conference on Complex Networks and their Applications
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Bitcoin's Crypto Flow Network2021

    • Author(s)
      Yoshi Fujiwara
    • Organizer
      International Conference on Big data in Economics, Science and Technology (BEST) 2021
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Bitcoin's Crypto Flow Network2021

    • Author(s)
      Yoshi Fujiwara
    • Organizer
      International Confereence Blockchain in Kyoto 2021, Kyoto University (February 17-18, 2021)
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research
  • [Presentation] Disaster and Countermeasure: Simulation on Nation-Wide Supply Chain Data2020

    • Author(s)
      Hiroyasu Inoue
    • Organizer
      The B.E.S.T. Workshop and a Satellite Meeting to the NetSci-X 2020, Complex Systems in Finance and Economy, Kyoto
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Hodge decomposition of Bitcoin money flow among big players2019

    • Author(s)
      Yoshi Fujiwara
    • Organizer
      University Blockchain Research Initiative (UBRI) Conference, October 2019 (Berkeley, USA)
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Influence of News in Crypto-asset Markets2019

    • Author(s)
      Shinya Kawata, Yoshi Fujiwara, and Hiwon Yoon
    • Organizer
      University Blockchain Research Initiative (UBRI) Conference, October 2019 (Berkeley, USA)
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Hodge decomposition of Bitcoin money flow among big players2019

    • Author(s)
      Yoshi Fujiwara
    • Organizer
      The 8th International Conference on Complex Networks and their Applications, Lisbon
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Funded Workshop] Blockchain in Kyoto 20212021

    • Related Report
      2020 Research-status Report

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Published: 2019-07-04   Modified: 2023-01-30  

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