Takuya Kataiwa

Affiliation: Fourth-year student, Department of Information and Social Sciences, Faculty of Informatics, Shizuoka University
Born: 2004, Ishikawa, Japan

I study informatics with a focus on design for a society where humans and AI coexist. Through the lenses of usable security and LLM security, I explore safe and trustworthy interactions between people and AI. I believe in translating theory into social applications.

Links
Portrait of Takuya Kataiwa

Research Interests

Keywords: Posthumanism design, usable security, LLM security

Research Achievements

International Conferences

  1. Enhancing LLM4Decompile with Obfuscated Source Code for Optimized Assembly Saito Ryota, Takuya Kataiwa, Tetsushi Ohki. The Network and Distributed System Security (NDSS) Symposium 2025. [details] [poster]
  2. Invisible Consent: Browser Automation by LLM Agents is Not Privacy-aware Ryota Saito, Takuya Kataiwa, Minato Takashima, Tetsushi Ohki. Extended Abstracts of the ACM CHI Conference on Human Factors in Computing Systems (CHI EA '26). 2026. [ACM DL]
  3. Secure and Usable Authentication Using Avatar Expression Blendshapes in Virtual Reality Natsuki Nagai, Tetsuro Takahashi, Takuya Kataiwa, Masakatsu Nishigaki, Tetsushi Ohki. Extended Abstracts of the ACM CHI Conference on Human Factors in Computing Systems (CHI EA '26). 2026. [ACM DL]

Domestic Conferences

  1. Invisible Consent: Browser Automation by LLM Agents is Not Privacy-aware Ryota Saito, Takuya Kataiwa, Masakatsu Nishigaki, Tetsushi Ohki. Computer Security Symposium 2025. 2025.
  2. Measuring Intrinsic Dimension of Token Embeddings Takuya Kataiwa, Cho Hakaze, Tetsushi Ohki. The 39th Annual Conference of the Japanese Society for Artificial Intelligence. 2025.
  3. Simulator for Social Norm Formation by Aggregating Individual Behavioural Decisions Jun Tajima, Takuya Kataiwa, Kenya Sasaki, Junya Morita. The 39th Annual Conference of the Japanese Society for Artificial Intelligence. 2025.
  4. Measuring Intrinsic Dimension of Embedding Representations Takuya Kataiwa, Cho Hakaze, Tetsushi Ohki. The 31st Annual Meeting of the Association for Natural Language Processing. 2025.
  5. A Method Using Dynamic Graph Neural Networks for Emotional Contagion in Local Communities Takuya Kataiwa, Junya Morita. The 21st Informatics Workshop. 2023.

Preprint

  1. Measuring Intrinsic Dimension of Token Embeddings Takuya Kataiwa, Cho Hakaze, Tetsushi Ohki. [arXiv]

Poster Presentations

  1. Effects of Expression Types in VR Facial Expression Recognition on Authentication Accuracy and Usability Natsuki Nagai, Tetsuro Takahashi, Takuya Kataiwa, Masakatsu Nishigaki, Tetsushi Ohki. The 2026 Symposium on Cryptography and Information Security. 2026.
  2. Evaluating Scalability in LLM-based Decompilation Using Source Code Obfuscation Ryota Saito, Takuya Kataiwa, Makoto Yamaguchi, Yoshinobu Kano, Tetsushi Ohki. The 20th Young Researchers' Symposium on Natural Language Processing. 2025. Sponsor Award.
  3. Does Training Order Affect Transfer Performance and Internal Representations in Multilingual Continual Pretraining? Makoto Yamaguchi, Takuya Kataiwa, Yoshinobu Kano. The 20th Young Researchers' Symposium on Natural Language Processing. 2025.
  4. Hypothesis Exploration of Kunji-dominant Volumes of the Man'yōshū Using KL Divergence of n-gram Models Shiori Shiratori, Takuya Kataiwa. The 20th Young Researchers' Symposium on Natural Language Processing. 2025.

Miscellaneous

  1. CPC Spring Camp 2025: A Student Participation Report Takuya Kataiwa, Hana Kubota, Momoha Hirose. Journal of the Robotics Society of Japan, Vol.44, No.5, pp.488–491. 2026.

Selected Programs

Fellowships and Research Development Programs

  1. Cybozu Labs Youth, 14th and 15th cohorts [Official]
  2. Nippon Foundation HUMAI Program, 1st and 2nd cohorts [Official] Distinguished graduate (Excellence Award, 1st HUMAI Essay Contest [Final Review])
  3. ADvance Lab, 2nd cohort [Official] Theme: Ensuring the safety and reliability of machine-learning model memory through geometry
  4. Security Camp National 2025, Class D [Official]
  5. 100 Program, 10th cohort (Summer 2026) — Accepted [Official]

Grants, Selected Projects, and Challenges

  1. MITOU IT Talent Scout and Development Program FY2026 — Accepted [Official] Theme: Communication augmentation via tactile gel interfaces (PM: Mizuki Oka)
    Jun 2026 | 7.5% (21/279) | Information-technology Promotion Agency, Japan
  2. Kansai Tech Creator Challenge (K-TCC) 2025 [Official] Theme: Holoprax: Extending cognition and the body to directly connect thought and action

Awards

University Awards

  1. Shizuoka University President's Award (FY2025) Mar 2026 | Ratio unavailable | Shizuoka University

Hackathons

  1. Gikuhaku 2025 vol.5 — Sponsor Award (WingArc 1st Award) Dec 2025 | 13.0% (3/23) | Hosted by Supporters
  2. Open HackU 2024 Tokyo — Excellence Award Feb 2024 | 6.7% (2/30) | Hosted by LY Corporation [Press Release]

Ideathons

  1. Urban Data Challenge 2025 — Gold Award Feb 2026 | 0.4% (1/229)
  2. Tekuno Ai 2025, University Student Division — Fighting Spirit Award Nov 2025 | Ratio unavailable | Hosted by the Tekuno Ai Executive Committee
  3. Hamamatsu City Well-being Idea Contest, University/Graduate/Vocational Student Division — Excellence Award Nov 2025 | Ratio unavailable | Hosted by LODU Inc. [Press Release] [News Article]
  4. Government Reform Student Ideathon and Hackathon — Technology Utilisation Award Aug 2025 | 11.1% (1/9) | Hosted by the Cabinet Secretariat [Press Release]
  5. Shizuoka University Ideathon and Datathon 2025 — Grand Prize Jun 2025 | 16.7% (1/6) | Co-hosted by Hamamatsu City and Shizuoka University
  6. Challenge Open Governance (COG 2024) — Semi-finalist Feb 2025 | 22.7% (25/110) | Hosted by the University of Tokyo

Business Contests

  1. IVS SPIKATHON 2026 — Winner Jul 2026 | Team count unavailable | Hosted by 4S Inc. (IVS2026 hosted by the IVS KYOTO Executive Committee) [Press Release 1] [Press Release 2] [Press Release 3] [Press Release 4] [Press Release 5]
  2. Tongali Business Plan Contest 2026 — 3rd Place (Tongali Award), Team I-Arm Jun 2026 | 18.8% (3/16) | Hosted by Tongali [Official]

Competitive Experience

Management Experience