KEIO RESEARCHERS INFORMATION SYSTEM

Other Affiliation 【 Display / hide 】

Other Affiliation 【 Display / hide 】

• QueryLift Inc, 特別顧問

Career 【 Display / hide 】

Career 【 Display / hide 】

• 2023.07

  -

  2025.03

  Sony CSL, Reseach Assistant

Academic Background 【 Display / hide 】

Academic Background 【 Display / hide 】

• 2024.04

  -

  2026.03

  Keio University, Graduate School of Media and Governance

  Graduate School, Completed, Master's course

• 2026.04

  Keio University, Graduate School of Media and Governacne

  Graduate School, Other, Doctoral course

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Informatics / Computer system (Distributed Algorithm)

• Informatics / Information security (Cryptographic Protocol)

• Informatics / Web informatics and service informatics (Generative Search Engine)

Research Keywords 【 Display / hide 】

Research Keywords 【 Display / hide 】

• Byzantine Fault Tolerant

• Distributed Algorithm

• State Machine Replication

Research Themes 【 Display / hide 】

Research Themes 【 Display / hide 】

• Generative Engine Optimization, 

  2025.06

  -

  Present

• Optimization of Byzantine-Fault-Tolerant Secret Sharing, 

  2024.04

  -

  Present

• Research on Fair Exchange on a Blockchain, 

  2022.12

  -

  Present

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• A Framework for Mitigation of Seller and Buyer's Dilemma with Transaction History

  Ryosuke Abe, Seiryo Kurita, Mariko Kobayashi, Riku Mochizuki, Hiroki Takemura, Shigeya Suzuki

  IEEE 2026 8th International Conference on Blockchain Computing and Applications (BCCA) (IEEE)   2026.11

  Research paper (international conference proceedings), Joint Work, Corresponding author, Accepted

• Assessing Attack Surfaces in Generative Search Engines through Publisher Attributes: A Case Study in Political Domains

  Riku Mochizuki, Shusuke Komatsu, Souta Noguchi and Kazuto Ataka

  The 35th ACM International Conference on Information and Knowledge Management (CIKM26) (ACM)   2026.11

  Research paper (international conference proceedings), Joint Work, Lead author, Corresponding author, Accepted

• Accountable Fair Exchange Protocols on Blockchain

  Riku Mochizuki, Ryosuke Abe, Shigeya Suzuki

  IEEE 50th Annual Computers, Software, and Applications Conference (COMPSAC) (IEEE)     968 - 974 2026.07

  Research paper (international conference proceedings), Joint Work, Lead author, Accepted

  　View Summary

  Fair exchange protocols on blockchain enable an atomic exchange of digital goods and cryptocurrency between untrusted parties. Two prominent protocols, Zero-Knowledge Contingent Payment (ZKCP) and FairSwap, guarantee fairness: either both parties receive the expected items (digital goods and cryptocurrency) or neither does. However, both protocols lack accountability: when an exchange terminates abnormally, the protocol cannot identify which party caused the failure. This lack of accountability undermines an applicability of fair exchange protocols in decentralized settings. To fill this gap, we identify a common accountability issue in both protocols and revise them by adding signature exchange and chaining. We measure the computational overheads of the revised protocols in our implementation and experiment.

  • Access to Document (DOI)

• WARASHIBE Protocol: Fair Data-Data Exchange on Blockchain

  Mochizuki, Riku and Abe, Ryosuke and Suzuki, Shigeya

  2025 IEEE International Conference on Blockchain and Cryptocurrency (ICBC)} (IEEE)   2026.06

  Research paper (international conference proceedings), Joint Work, Lead author, Accepted

• 投票済証明書発行システムの設計

  橋本 晃太朗, 望月 理来, 阿部 涼介, 曽我 悠真, 鈴木 茂哉

  DICOMO2026 (情報処理学会)   2026.06

  Research paper (conference, symposium, etc.), Corresponding author

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Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• INTRODUCTION TO PROGRAMMING 2

  2026, Undergraduate (liberal arts), Lecture, Within own ｆaculty

• Fundamental of Information Technology 2

  2026, Autumn Semester, Undergraduate (liberal arts), Lecture, Within own ｆaculty

Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• Information Processing Society of Japan, 

  2026.01

  -

  Present

• The Database Society of Japan , 

  2026.01

  -

  Present

• The Association for Natural Language Processing, 

  2026.01

  -

  Present

• Association for Computing Machinery (ACM), 

  2024.12

  -

  Present