Takuya Kataiwa

🇯🇵 🇬🇧

Affiliation: 4th‑year, Department of Information & 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, and I value translating theory into social applications.

Research Profiles / Links:
Hatena Blog · GitHub · Qiita · LinkedIn · Researchmap

Research Interests

Keywords: Posthumanism design, Usable security, LLM security

Research Achievements

International Conference

• 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] [PDF] [poster]
• 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]
• 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 Conference

• Measuring Intrinsic Dimension of Token Embeddings
  Takuya Kataiwa, Cho Hakaze, Ohki Tetsushi.
  The 39th Annual Conference of the Japanese Society for Artificial Intelligence (2025).
  [details]
• 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).
  [details]
• Measuring Intrinsic Dimension of Embedding Representations
  Takuya Kataiwa, Cho Hakaze, Ohki Tetsushi.
  The 31st Annual Meeting of the Association for Natural Language Processing (2025).
  [details] [PDF]
• A Method Using Dynamic Graph Neural Networks for Emotional Contagion in Local Communities
  Takuya Kataiwa, Junya Morita.
  The 21st Informatics Workshop (2023).
  [details]

Preprint

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

Posters

1. Effects of Expression Types in VR Facial Expression Recognition on Authentication Accuracy and Usability
   Kazuki Nagai, Tetsuro Takahashi, Takuya Kataiwa, Masakatsu Nishigaki, Tetsushi Ohki.
   The 2026 Symposium on Cryptography and Information Security — Poster presentation.

Misc

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. [J-STAGE]

Fellowships & Programs

• Cybozu Labs Youth (14th & 15th cohorts) — Accepted | [Official]
• Advance Lab (2nd cohort) — Accepted | [Official]
  Theme: Ensuring safety & reliability of machine‑learning model memory via geometric analysis
• UT‑Lab Membership — Accepted | [Official] [details]
• Security Camp National 2025 (Class D) — Alumni | [Official]
• Nippon Foundation HUMAI Program (1st & 2nd cohorts) — Accepted | [Official]
  Distinguished graduate (Excellence Award, 1st HUMAI Essay Contest [Final Review])
• MITOU Program FY2026 (IPA — Information-technology Promotion Agency, Japan) — Accepted | [Results]
  Theme: Communication augmentation via tactile gel interfaces (PM: Mizuki Oka) (Jun 2026 | Top 7.5% – 21 of 279 proposals)

Awards

• University Award
  1. Shizuoka University President's Award (FY2025) (Mar 2026 | Ratio unavailable | Shizuoka University)
• Hackathon
  1. 技育博2025.vol5 (Tech Education Expo) — Sponsor Award (WingArc 1st Award) (Dec 2025 | 13.0% (3/23) | Hosted by Supporters)
  2. Open HackU 2024 Tokyo — Excellence Award (Top 6.7% – 2 of 30 teams) — Hosted by LINE Yahoo [Press Release]
• Ideathon — Urban Data Challenge (UDC2025) — Gold Award (Top 0.4% – 1 of 229) (Feb 2026)
  Tekuno Ai 2025 — Fighting Spirit Award (University Student Division) — Hosted by the Tekuno Ai Executive Committee (Nov 2025)
  Hamamatsu City Well-being Idea Contest (University/Graduate/Vocational Student Division) — Excellence Award (Unknown) — Hosted by LODU Inc. [Press Release]
  Government Reform Student Ideathon & Hackathon — Technology Utilization Award (Top 11.1% – 1 of 9) — Hosted by the Cabinet Secretariat [Press Release]
  Shizuoka University Ideathon & Datathon 2025 — Grand Prize (Top 16.7% – 1 of 6)
  Challenge Open Governance (COG 2024) — Semi‑Finalist (Top 22.7% – 25 of 110)

Competitive Experience

• Competitive Programming: AtCoder — Algorithm Green / Heuristics Cyan
  Mathematics Competition: Online Math Contest — Aqua
  CTF (Capture The Flag): team: teapp
  
• iGEM HG‑Tokyo — Advisor (2025‑04 – 2025‑12)
  Gold Medal • Presentation — Top 6.8% (10 of 146) • Village — Top 10.9% (5 of 46) • Best Integrated Human Practices
  [Twitter]

Management Experience

• ANCHOR — Agora for Neuroscience, Consciousness, Human, Organisms & Related Research (2024‑10 – 2025‑12)
  Reading group on computational & cognitive neuroscience. [Official] [Discord]
• CPC Spring Camp Executive Committee
  Symbol Emergence Outreach Team — Committee Member (2024‑12 – Present) [Official] [Official] [Twitter] [YouTube] [Note]
• IYNA Japan Chapter — Advisor (2024‑12 – Present) [Official] [Twitter] [Instagram] [Note]

Other

• Selected Quotations (Japanese)

I enjoy deep conversations, great food, and travelling. Learning something new and widening my worldview is my greatest motivation.