Updated on 2026/04/28

写真a

 
ishii masahiro
 
Organization
School of Computing Visiting Associate Professor
Title
Visiting Associate Professor
External link

Degree

  • 博士(工学) ( 奈良先端科学技術大学院大学 )

Research Interests

  • Cybersecurity

  • Public-key cryptography

  • Network security

  • Elliptic-curve cryptography

  • Post-quantum cryptography

  • Pairing-based cryptography

  • Efficient software implementation of cryptographic algorithms

  • Computer algebra

Research Areas

  • Informatics / Information network

  • Informatics / Information security

  • Natural Science / Algebra

Education

  • Nara Institute of Science and Technology   Graduate School of Information Science

    2023.4 - 2026.9

      More details

    Notes: Doctoral course

    researchmap

  • Nara Institute of Science and Technology   Graduate School of Information Science

    2011.4 - 2013.3

      More details

    Notes: Master's course

    researchmap

  • Nagoya University   Graduate School of Mathematics

    2009.4 - 2011.3

      More details

  • Hiroshima University   Faculty of Science   Department of Mathematics

    2005.4 - 2009.3

      More details

Research History

  • Showa Women's University   Faculty of Informatics   Lecturer

    2026.4

      More details

  • Institute of Science Tokyo   School of Computing   Visiting Associate Professor

    2026.4

      More details

  • Institute of Science Tokyo   Center for Information Infrastructure   Assistant Professor

    2024.10 - 2026.3

      More details

  • National Institute of Advanced Industrial Science and Technology   Cyber Physical Security Research Center   Collaborative Researcher

    2021.5

      More details

  • Tokyo Institute of Technology   Global Scientific Information and Computing Center   Assistant Professor

    2018.1 - 2024.9

      More details

  • Tokyo Institute of Technology   School of Computing   Specially Appointed Assistant Professor

    2016.10 - 2017.12

      More details

▼display all

Professional Memberships

  • INFORMATION PROCESSING SOCIETY OF JAPAN

      More details

  • Association for Computing Machinery

      More details

  • THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS

      More details

Committee Memberships

  • Information Processing Society of Japan   Secretary of Computer Security Group  

    2026.4 - 2028.3   

      More details

    Committee type:Academic society

    researchmap

  • Information Processing Society of Japan   Steering Committee Member of Computer Security Group  

    2021.4 - 2025.3   

      More details

    Committee type:Academic society

    researchmap

Papers

  • Effective Analysis of Encrypted Traffic for Mining Detection

    Masahiro Ishii, Satoshi Shibuya, Keisuke Tanaka

    Proceedings of the 12th International Conference on Information Systems Security and Privacy - Volume 1: ICISSP   61 - 72   2026.3

     More details

    Authorship:Lead author, Corresponding author   Publishing type:Research paper (international conference proceedings)   Publisher:SCITEPRESS - Science and Technology Publications  

    DOI: 10.5220/0014316300004061

    researchmap

  • An Optimization for Efficient Computation of Multiradical (3, 3)-isogenies on Jacobians Reviewed

    Masahiro Ishii, Daiki Hayashida

    Mathematics for Industry   351 - 368   2025.10

     More details

    Authorship:Lead author, Corresponding author   Publishing type:Part of collection (book)   Publisher:Springer Nature Singapore  

    Abstract

    In this paper, we focus on isogenies over abelian varieties for isogeny-based cryptography and efficient computation of the hash function using multiradical (3, 3)-isogenies. In particular, we performed a detailed analysis of the explicit formulae to compute multiradical (3, 3)-isogenies and optimized many parts for the efficient hash function. We optimized the formulae manually and achieved a $$16.8\%$$ reduction in complexity arithmetic operations compared to the implementation of the previous work. In particular, we achieved an efficiency improvement of about $$86.5\%$$ for the most complicated part of the hash function excluding the Gröbner basis computation. In addition, we provided a comparison of hash functions using isogenies on elliptic curves and Jacobians of genus 2 curves. We discuss further improvements and optimization of the multiradical (3, 3)-isogenies that make the hash function based on them faster than in the case of elliptic curves.

    DOI: 10.1007/978-981-96-1218-5_18

    researchmap

  • Improving Emotion Estimation Accuracy by Integrating Multimodal Features from Audio and Video Reviewed

    Aina Ito, Yuka Kato, Masahiro Ishii

    2025 IEEE 14th Global Conference on Consumer Electronics (GCCE)   546 - 548   2025.9

     More details

    Authorship:Last author   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    DOI: 10.1109/gcce65946.2025.11275062

    researchmap

  • Early Detection of Student Dropout Risk in Higher Education Using SMOTE-CatBoost Pipeline Reviewed

    Rina Katagiri, Yuka Kato, Masahiro Ishii

    2025 IEEE 14th Global Conference on Consumer Electronics (GCCE)   538 - 540   2025.9

     More details

    Authorship:Last author   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    DOI: 10.1109/gcce65946.2025.11275212

    researchmap

  • Multi-label Classification of Cybersecurity Text with Distant Supervision Reviewed

    Masahiro Ishii, Kento Mori, Ryoichi Kuwana, Satoshi Matsuura

    Proceedings of the 17th International Conference on Availability, Reliability and Security   ( 93 )   1 - 9   2022.8

     More details

    Authorship:Lead author   Publishing type:Research paper (international conference proceedings)   Publisher:ACM  

    DOI: 10.1145/3538969.3543795

    researchmap

  • A Study of Classification of Texts into Categories of Cybersecurity Incident and Attack with Topic Models Reviewed

    Masahiro Ishii

    ICISSP: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON INFORMATION SYSTEMS SECURITY AND PRIVACY   1   639 - 646   2020.2

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.5220/0009099606390646

    Web of Science

    researchmap

  • A RAT Detection Method by Using Packet Entropy on Early Intrusion Stage Reviewed

    M. Ishii, M. Uno, A. Inomata, I. Arai, K. Fujikawa

    IEICE Transactions on Communications (Japanese Edition)   J101-B ( 3 )   220 - 232   2018

     More details

    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

    researchmap

  • Fast Modular Arithmetic on the Kalray MPPA-256 Processor for an Energy-Efficient Implementation of ECM Reviewed

    Masahiro Ishii, Jeremie Detrey, Pierrick Gaudry, Atsuo Inomata, Kazutoshi Fujikawa

    IEEE TRANSACTIONS ON COMPUTERS   66 ( 12 )   2019 - 2030   2017.12

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TC.2017.2704082

    Web of Science

    researchmap

  • A Weil Pairing on a Family of Genus 2 Hyperelliptic Curves with Efficiently Computable Automorphisms Reviewed

    Masahiro Ishii, Atsuo Inomata, Kazutoshi Fujikawa

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E100A ( 1 )   62 - 72   2017.1

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1587/transfun.E100.A.62

    Web of Science

    researchmap

  • Pairings on Hyperelliptic Curves with Considering Recent Progress on the NFS Algorithms. Reviewed

    Masahiro Ishii

    Mathematical Modelling for Next-Generation Cryptography: CREST Crypto-Math Project (Takagi, T., Wakayama, M., Tanaka, K., Kunihiro, N., Kimoto, K. and Duong, D. H., eds.)   81 - 96   2017

     More details

    Authorship:Lead author   Publishing type:Part of collection (book)   Publisher:Springer Singapore  

    DOI: 10.1007/978-981-10-5065-7_5

    researchmap

  • Pairings on Hyperelliptic Curves of Genus 2 at High Security Levels

    Masahiro Ishii

    Nara Institute of Science and Technology   2016.9

     More details

    Language:English   Publishing type:Doctoral thesis  

    researchmap

  • A Construction of a Twisted Ate Pairing on a Family of Kawazoe-Takahashi Curves at 192-bit Security Level and Its Cost Estimate Reviewed

    M. Ishii, A. Inomata, K. Fujikawa

    Proceedings of the 2nd International Conference on Information Systems Security and Privacy (ICISSP 2016)   432 - 439   2016

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (international conference proceedings)  

    researchmap

  • Parallel GPU Implementation of $\eta_T$ Pairing over Fields of Characteristic Two Reviewed

    M. Ishii, A. Inomata, K. Fujikawa

    ICNCS 2014, International Journal of Computer and Communication Engineering   3 ( 3 )   193 - 198   2014

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:International Academy Publishing  

    researchmap

▼display all

MISC

  • Authentication with RGB-D Feature Correspondences on the Washington RGB-D Dataset

    Seigo Kawachi, Masahiro Ishii, Satoshi Matsuura

    2026.1

     More details

  • An Analysis of Root Causes for Secret Leakage in GitHub Repositories

    Naseer Ahmad Noor, Masahiro Ishii, Keisuke Tanaka

    2026 Symposium on Cryptography and Information Security   2026.1

     More details

    Language:English  

    researchmap

  • Analysis of Oblivious HTTP Traffic for Map Services Considering Image Formats and Scaling

    Tsubasa Saito, Masahiro Ishii, Keisuke Tanaka

    2026.1

     More details

  • Low-cost Malware Detection Using PE Headers

    Rikuto Gunji, Masahiro Ishii, Satoshi Matsuura

    2026.1

     More details

  • キャッシュ機構におけるアクセス傾向を考慮したDRAM/SSD割り当ての最適化 Reviewed

    山本悠史, 石井将大, 松浦知史

    第33回マルチメディア通信と分散処理ワークショップ論文集   99 - 105   2025.11

     More details

  • On the Problems of Tree-Chain

    R. Tomita, M. Ishii, T. Oda, K. Tanaka, Y. Tamura, X. Defago, T. Naka, A. Nakai, K. Mori

    2025.1

     More details

  • Analysis on Oblivious HTTP Traffic of a Map Service

    S. Baba, M. Ishii, K. Tanaka

    2025.1

     More details

  • A Study on Anomaly Detection Method for IoT using Isolation Forest

    D. Sugata, M. Ishii, S. Matsuura

    32 - 38   2024.10

     More details

  • Mining Detection in Encrypted Traffic

    S. Shibuya, M. Ishii, K. Tanaka

    2024.1

     More details

  • An analysis of the cost to find an isomorphism between hyperelliptic curves in isogeny-based cryptography

    D. Hayashida, M. Ishii

    122 ( 428 )   61 - 67   2023.3

     More details

    Authorship:Last author   Language:Japanese  

    researchmap

  • A study of explicit formulae of the isogenies between abelian surfaces

    D. Hayashida, M. Ishii

    121 ( 429 )   122 - 129   2022.3

     More details

    Authorship:Last author   Language:Japanese  

    researchmap

  • Multi-label Classification of Cybersecurity Text with Distant Supervision

    M. Ishii, K. Mori, R. Kuwana, S. Matsuura

    2022.1

     More details

    Authorship:Lead author   Language:Japanese  

    researchmap

  • A Note on Group Membership Check in Elliptic Curves for Pairings

    T. Yasuda, M. Ishii, T. Teruya

    2022.1

     More details

    Language:Japanese  

    researchmap

  • Concurrent Group Operations on TreeKEM

    Y. Koyanagi, M. Ishii, K. Tanaka

    2022.1

     More details

    Language:English  

    researchmap

  • Efficient Pairing Algorithms Using Twists of Degree 3

    1080 - 1087   2020.10

     More details

    Authorship:Lead author   Language:Japanese  

    CiNii Research

    researchmap

  • Dropout-Tolerant Mental Poker Protocol with Small Deposit and Optimal Upper Bound on Number of Dropouts

    T. Oozu, M. Ishii, K. Tanaka

    2020.1

     More details

    Language:English  

    researchmap

  • Cryptocurrency Mining Communications with Deep Learning

    S. Endo, M. Ishii, K. Tanaka

    2020.1

     More details

    Language:Japanese  

    researchmap

  • セキュリティ事案における知見の蓄積・活用を可能とする対応フローの提案と実装

    森健人, 石井将大, 松浦知史, 金勇, 北口善明, 友石正彦

    情報処理学会研究報告   2019-IOT-46 ( 2 )   1 - 8   2019.6

     More details

    Language:Japanese  

    researchmap

  • 東工大CERTにおけるインシデント対応の分析とその自動化に関する考察

    石井将大, 森健人, 松浦知史, 金勇, 北口善明, 友石正彦

    情報処理学会研究報告   2018-IOT-43 ( 2 )   1 - 8   2018.9

     More details

    Authorship:Lead author   Language:Japanese  

    researchmap

  • Approximation Algorithms for k-Anonymity with Large k

    K. Yamada, T. Ohzu, M. Ishii, K. Tanaka

    2018.1

     More details

    Language:Japanese  

    researchmap

  • Evaluation of Anomaly Detection Algorithms on Cluster Sequence of Proxy Server Logs

    2018.1

     More details

    Language:Japanese  

    researchmap

  • Complexity of k-Anonymity with Large k

    T. Ohzu, K. Yamada, M. Ishii, K. Tanaka

    2018.1

     More details

    Language:Japanese  

    researchmap

  • Network based detection of Remote Access Trojan communication by using packet entropy on early instruction stage

    116 ( 491 )   41 - 46   2017.3

     More details

    Language:Japanese  

    CiNii Books

    researchmap

  • A Construction of an Optimal Pairing on a Family of Kawazoe-Takahashi Curves and Its Cost Estimate

    2015 ( 3 )   258 - 265   2015.10

     More details

    Authorship:Lead author   Language:English  

    CiNii Research

    researchmap

  • An Efficient Implementation of nT Pairing on Genus 2 Hyperelliptic Curve and Discrete Logarithms in Finite Fields of Characteristic 2

    2013 ( 4 )   673 - 679   2013.10

     More details

    Authorship:Lead author   Language:Japanese  

    researchmap

  • RA-006 Normal Basisを用いた多項式基底間の基底変換(A分野:モデル・アルゴリズム・プログラミング,査読付き論文) Reviewed

    石井 将大, 猪俣 敦夫, 藤川 和利

    情報科学技術フォーラム講演論文集   12 ( 1 )   41 - 48   2013.8

     More details

    Authorship:Lead author   Language:Japanese   Publisher:FIT(電子情報通信学会・情報処理学会)運営委員会  

    有限体上の算術とその実装は,暗号,符号理論に基づく様々な応用技術において,最も重要なものである.又,有限体の基底変換を用いることにより,その定義体に適した高速な実装が可能となり,更に,有限体上の算術に関して,特別な基底を用いた多くの効率的なアルゴリズムが研究されている.本研究では,同型な有限体における任意の多項式基底間の基底変換に関して,従来のEDF(Equal Degree Factorization)を用いた手法に対して,normal basisへの基底変換を用いることによる,計算コストのより小さい手法を提案する.更に,normal basisを成す元の確率的な探索手法に関しても幾つか考察を与える.提案手法により,多項式基底間の基底変換に関して,拡大体の拡大次数kについて概ね1/kのコスト削減を実現した.又,提案アルゴリズムについて,EDFを用いた手法に対し,計算コストの比較を行った.

    CiNii Books

    researchmap

  • A study of parallel computation of pairings on hyperelliptic curves with pairing-friendly fields

    2012 ( 3 )   843 - 848   2012.10

     More details

    Authorship:Lead author   Language:English  

    CiNii Research

    researchmap

▼display all

Awards

  • 第33回マルチメディア通信と分散処理ワークショップ 優秀論文賞

    2025.11   キャッシュ機構におけるアクセス傾向を考慮したDRAM/SSD割り当ての最適化

    山本悠史, 石井将大, 松浦知史

     More details

  • 2025 IEEE 14th Global Conference on Consumer Electronics, Excellent Student Paper Awards Silver Prize

    2025.9  

    Rina Katagiri, Yuka Kato, Masahiro Ishii

     More details

  • コンピュータセキュリティシンポジウム2020奨励賞

    2020.10   3次ツイストを利用した効率的なペアリングアルゴリズム

    石井将大, 照屋唯紀, 安田貴徳

     More details

Research Projects

  • 混合暗号化通信の分析基盤の構築

    2024 - 2026

    科学技術振興機構  戦略的な研究開発の推進 戦略的創造研究推進事業 ACT-X 

    石井 将大

      More details

    Authorship:Principal investigator 

    組織内で観測される通信の大半は暗号化され、表層的な分析ではサイバーセキュリティの脅威となる悪性通信の検知は容易ではありません。本研究では、特にVPN暗号化トンネルなどで複数の通信路(ストリーム)が多重化された、混合通信の暗号化データに対する通信の分類・検知を行います。さらに、学習モデルの高精度化を実現するため、多様な暗号化通信に対応したデータセット作成と特徴分析機構を持つ分析基盤を構築します。

    researchmap

    J-GLOBAL

  • 実用的なペアリング暗号の開発

    Grant number:21K17740  2021.4 - 2024.3

    日本学術振興会  科学研究費助成事業  若手研究

    石井 将大

      More details

    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

    本研究の目的は,効率的なペアリングベース暗号に寄与するペアリングとその構成法を提案し,適切な暗号パラメータの探索を行い,その成果をペアリング暗号の利用者・実装者に提供することである.
    2021年度では,特にペアリング暗号において扱われる数の正当性を担保するための技術の一つである,楕円曲線の有理点群における群所属判定の効率化に取り組んだ.効率的なペアリングを構成する際によく利用される楕円曲線族をより包括的に扱い,各曲線族における群所属判定手法と,背景にある数学的理論を整理し群所属判定が曲線族の性質を用いてどのように記述されるかを明らかにした.これらの成果を国内会議SCIS2022で報告し,現在研究対象を更に拡げ当該手法について精査を行っている.群所属判定の研究において明らかにした各曲線族の数学的性質等を活用し,引き続き実用的なペアリング暗号の構築のための研究開発を遂行する.
    また,楕円曲線間の同種写像に着目し,ペアリングフレンドリ曲線のみならず,同種写像によって移り合うより広範の楕円曲線を対象とし,安全かつ効率的なペアリングの構成に寄与する曲線やパラメータ探索を行う.
    近年耐量子計算機暗号の一つの候補として注目を浴びている,楕円曲線,あるいはより高次のアーベル多様体をそれら多様体間に定義される同種写像を利用した同種写像暗号の研究を進めており,ISEC研究会において種数2のアーベル多様の間の同種写像を計算するためのexplicit formulaeの効率化について報告している.これらの研究で得られる同種写像の詳細な数学的性質,理論をペアリングに適した曲線の構成や,安全性解析に活用する.

    researchmap

Teaching Experience

  • Seminar on Data Science ⅡC

    2025.9 Institution:Showa Women's University

     More details

  • Mathematics C

    2025.4 Institution:Showa Women's University

     More details

  • Seminar in Information and Sciences

    2024.4 - 2025.3 Institution:Tokyo Woman's Christian University

     More details

  • Computer Programming 1

    2023.4 - 2025.8 Institution:Tokyo University of Science

     More details

  • Operating System

    2019.9 - 2025.3 Institution:Tokyo Woman's Christian University

     More details