Takuma Takeuchi

Takuma Takeuchi

A research scientist in blockchain technologies

Takuma Takeuchi

My research interests include blockchain security, blockchain interoperability, and related issues. Currently, I am approaching these issues with research and open source development activities.

Research interests

  • Blockchain technology, including blockchain security and blockchain interoperability
  • Applied statistics, including statistical experimental design and quantum hypothesis testing
  • Rubik’s Cube

Curriculum vitae

Work experience

  • Apr.2013–now: Fujitsu Limited
    • Apr.2023–now: Senior Research Manager, Fujitsu Research, Fujitsu Limited
    • Apr.2022–Mar.2023: Research Manager, Fujitsu Research, Fujitsu Limited
    • Oct.2021–Mar.2022: Senior Researcher, Fujitsu Research, Fujitsu Limited
    • Apr.2021–Sep.2021: Researcher, Fujitsu Research, Fujitsu Limited
    • Apr.2013–Mar.2021: Researcher, Fujitsu Laboratories Ltd.
  • May.2020–now: Linux Foundation Decentralized Trust / Hyperledger Foundation
    • Sep.2024–now: Project Maintainer, Hyperledger Cacti, Linux Foundation Decentralized Trust
    • Sep.2022–Aug.2024: Project Maintainer, Hyperledger Cacti, Hyperledger Foundation
    • May.2020–Sep.2022: Project Maintainer, Hyperledger Cactus, Hyperledger Foundation
  • Apr.2023–Mar.2024: Fujitsu Research of Europe Ltd.
    • Apr.2023–Mar.2024: Senior Research Manager, Fujitsu Research of Europe Ltd.
  • Jan.2022–Mar.2023: Fujitsu Research of America, Inc.
    • Apr.2022–Mar.2023: Research Manager, Fujitsu Research of America, Inc.
    • Jan.2022–Mar.2022: Member of Research Staff, Fujitsu Research of America, Inc.
  • Sep.2010–Mar.2011: Bioinformatics Institute for Global Good, Inc.
    • Sep.2010–Mar.2011: Part-time Software Developer, Bioinformatics Institute for Global Good, Inc.

Education

  • Apr.2011–Mar.2013: Master’s degree of Informatics, Kyoto University
    • Apr.2011–Mar.2013: Department of Applied Mathematics and Physics, Graduate School of Informatics, Kyoto University
  • Apr.2007–Mar.2011: Bachelor’s degree of Engineering, The University of Tokyo
    • Apr.2009–Mar.2011: Department of Mathematical Engineering and Information Physics, Faculty of Engineering, The University of Tokyo
    • Apr.2007–Mar.2009: Division of Natural Sciences 1, College of Arts and Sciences, The University of Tokyo

Research and development activities

Referred journals and conferences

  • Florian Zimmer, Janosch Haber, Mayuko Kaneko, Takuma Takeuchi: “Towards Levels of Assurance for Data Trustworthiness - A Novel Framework to Promote Trust in Inter-Organisational Data Sharing” (workshop paper), 18th Workshop on Social and Human Aspects of Business Process Management (BPMS2 2025), 19th International Conference on Research Challenges in Information Science (RCIS2025), Spain, 2025.
  • Takuma Takeuchi, Peter Somogyvari, Tracy Kuhrt, Venkatraman Ramakrishna, Susumu Toriumi: “Panel Discussion: Blockchain Interoperability with Hyperledger Cactus, Weaver, and YUI” (presentation), Hyperledger Global Forum 2022 (HGF2022), Ireland, 2022. [Youtube]
  • Jim Zhang, Sophia Lopez, Peter Somogyvari, Venkatraman Ramakrishna, Takuma Takeuchi: “Panel Discussion: All Things Cross-Chain” (presentation), Hyperledger Global Forum 2022 (HGF2022), Ireland, 2022. [Youtube]
  • Shingo Fujimoto, Takuma Takeuchi, Yoshiki Higashikado. “Secure Blockchain Interworking Using Extended Smart Contract” (journal), IEICE Transactions on Information and Systems 2022.
  • Takuma Takeuchi. “A blockchain interoperability solution for creating token economies - Hyperledger Cactus” (presentation), DeveloperWeek2022, Virtual and USA, 2022.
  • Shingo Fujimoto, Yoshiki Higashikado, Takuma Takeuchi. “ConnectionChain: Secure Interworking of Blockchains” (proceeding), The International Symposium on Blockchain Computing and Applications (BCCA2019), Spain, 2019.
  • Takuma Takeuchi, Yoshiki Higashikado, Shingo Fujimoto. “A secure cross-chain platform for business blockchain applications” (poster), The 14th International Workshop on Security (IWSEC2019), Japan, 2019.
  • Takuma Takeuchi, Toshiya Shimizu, Ken Kamakura, Takeshi Shimoyama, Hiroshi Tsuda. “A Limited-Use Asset Management System on the Blockchain Platform with an Extended Open Assets Protocol” (proceeding), The 23rd Annual International Conference on Advanced Computing and Communications (ADCOM2017), India, 2017.
  • Fuyuhiko Tanaka, Takuma Takeuchi. “Hypothesis testing of a maximally entangled state under the unknown unitary process” (poster), Quantum Information Processing 2012 (QIP2012), Canada, 2011.

Non-referred presentations

  • Takuma Takeuchi, Hiroto Sekido. “An approximate approach to E-optimal designs for weighted polynomial regression by using Tchebycheff systems and orthogonal polynomials” (poster), China-Japan Joint Workshop on Integrable Systems 2013, Japan, 2013.
  • Takuma Takeuchi, Hiroto Sekido. “On the E-optimal design of weighted polynomial regression using the Tchebycheff system and orthogonal polynomials” (poster), The 7th JSS Spring Meeting (The Japan Statistics Society), Japan, 2013.
  • Takuma Takeuchi, Ryuta Hashimoto, Daishi Aiura, Yin Xin, Takuya Kato, Kazuma Tsukamoto, Takeru Matsuda. “5x5x5 Rubik’s Cube Solver and its subprogram with GAP” (presentation), Risa/Asir Conference 2012, Japan, 2012.
  • Takuma Takeuchi, Fuyuhiko Tanaka. “Hypothesis Testing of Quantum State Models with Disturbing Parameters” (presentation), Japan Federation of Statistical Science Associations, Japan, 2011.

Invited presentations

  • Takuma Takeuchi. “An introduction to research activities of security and blockchain on Fujitsu” (presentation), Human Network for Researchers toward Advanced Telecommunications (AC Net), Online, 2021.
  • Takuma Takeuchi. “The overview of Hyperledger Cactus V0.4 and its plan for future development” (presentation), Hyperledger Tokyo Meetup, Online, 2021. [Slideshare(Japanese)], [Youtube(Japanese)]
  • Takuma Takeuchi. “An introduction to the new project, Hyperledger Cactus” (presentation), Hyperledger Tokyo Meetup, Online, 2020. [Slideshare(Japanese)], [Youtube(Japanese)]

Technical articles

  • Peter Somogyvari, Jagpreet Singh Sasan, Izuru Sato, Takuma Takeuchi, Venkatraman Ramakrishna, Sandeep Nishad, Krishnasuri Narayanam, Dhinakaran Vinayagamurthy: “Introducing Hyperledger Cacti, a multi-faceted pluggable interoperability framework” (technical blog), Hyperledger Blog, 2022. [Blog]
  • Peter Somogyvari, Takuma Takeuchi: “Hyperledger Cactus: Release V1 on the Road to General Blockchain Integration” (technical blog), Hyperledger Blog, 2022. [Blog]

Interview articles

  • Takuma Takeuchi: “Thinking outside of the box – focusing on boundaries between multiple heterogeneous technologies to build new attractive technology” (interview blog), Researcher’s Dream, Fujitsu Research, 2022. [Blog]

Open source software development

Awards

  • Best Idea and Use Case Award, Smart Contract Japan 2016 Blockchain Hackathon, 2016.
  • Best Student Presentation Award, The 7th JSS Spring Meeting (Japan Statistical Society), 2013.