Biography#
I am a security engineer and researcher working on threat analysis to develop practical defensive designs and frameworks. (Notes). My background includes web application development, cloud infrastructure, and technical leadership. Alongside my work, I enjoy taking on challenges like CTFs and privacy competitions.
Experience#
- Research Assistant / M.S. Student, Georgetown University — Washington, DC, USA–present
- Chief Technology Officer, Physical Control Center Inc. — Osaka, Japan–
- Researcher, Gunma University — Gunma, Japan–
- Researcher, Commonwealth Cyber Initiative — Virginia, USA–
- Earlier Software Engineering Roles across Several Companies — Japan–
Highlights#
- Invited Talk — “From Incident Analysis to Security Architecture: Lessons for Bridges and Layer 2 Systems,” Research Committee #94, The Foundation for the Promotion of Industrial Science
- Earned OSCP/OSCP+
- Invited Talk — “Block Hijacking Attack,” Research Committee #94, The Foundation for the Promotion of Industrial Science
- 3rd Place (Team), C2C CTF 2025 Finals
- CSEC Excellent Research Award — IPSJ SIG Computer Security (CSEC)
- 2nd Place, iPWS Cup 2024
- 1st Place (Team), iPWS Cup 2023
First-Author Publications#
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"Integration of PSI-CA and Differential Privacy for APPI Compliance" Authors: Kabuto Okajima Diaz Zazueta, Koji Chida
Venue: The 111th IPSJ SIG Computer Security (CSEC) Joint Research Meeting, Niigata, Japan -
"Block Hijacking Attack: Impact Evaluation on Liquid Network and Design Insights for Blockchain-based Scaling Solutions" Authors: Kabuto Okajima, Shin’ichiro Matsuo, Koji Chida
Proceedings: 2025 IEEE International Conference on Blockchain and Cryptocurrency (ICBC), Pisa, Italy -
"A Study on Anonymization Through Participation in iPWS Cup 2023" Authors: Kabuto Okajima, Koji Chida
Proceedings: International Workshop on Security, IWSEC 2024, Kyoto, Japan