About me

Japanese version is available here.

Name: Ryutaro Nishizaka

Interests: Computer Science / Cybersecurity / Hardwares / System Programs

I study security at low layers such as CPUs, TEEs, operating systems, and hypervisors.

Publications

Ryutaro Nishizaka, Yudai Fujiwara, Takuya Shimizu, Kazushi Kato, Yuichi Sugiyama: Towards LLM-Resistant Software Protection: Agent Failure Patterns in CTF Reverse Engineering, Workshop on Binary Analysis Research (BAR) 2026 Co-located with NDSS Symposium 2026, February 2026.
Ryutaro Nishizaka, Kazushi Kato, Yuichi Sugiyama: IPSM-Based Test Case Minimization for Network Protocol Implementations, The 19th International Workshop on Search-Based and Fuzz Testing Co-located with ICSE 2026, April 2026.

Ryutaro Nishizaka, Hidemasa Kawasaki, Shinya Takamaeda, Soramichi Akiyama: Privilege Escalation Attack to RISC-V Keystone TEE via RowHammer, Computer Security Symposium 2025 (CSS), pp. 1875–1882. CSS Outstanding Paper Award.
Ryutaro Nishizaka, Kazushi Kato, Yuichi Sugiyama: State-Aware Test Case Minimization for Network Protocol Implementations, Computer Security Symposium 2025 (CSS), pp. 937–944.

Computer Security Symposium 2025 (CSS2025): Presented two first-author papers; one received the Outstanding Paper Award.
- Privilege Escalation Attack to RISC-V Keystone TEE via RowHammer, CSS Outstanding Paper Award.
- State-Aware Test Case Minimization for Network Protocol Implementations
Information Processing Society of Japan (IPSJ) 87th National Convention: Poster presentation — Evaluating the Feasibility of RowHammer Attacks against Keystone.
SECCON Beginners CTF 2025 (CTF4b): Served on the organizing team; authored three pwn challenges (pivot4b / pivot4b++ / TimeOfControl).
SecHack365: Accepted into the Learning Course (Sakai seminar).
Media Coverage: A second interview featured on the school website — A School that Fosters the Power to Pioneer: High School Student × Teacher Dialogue—Learning at Rikkyo Niiza.

CognitiveHack Japan 2024: Champion, Junior Division and Junior School Division.
JST Global Science Campus Experts in Information Science: Selected for the 5th cohort.
Informatics Olympiad: Qualified for the final round.
Machine Learning Specialization: Completed.
UK-Japan Young Scientists Workshop: Completed.

Registered Information Security Specialist: Passed at the youngest age; became a registered specialist.
Security Camp National Conference: Completed Class C (Threat Analysis).
Security Mini Camp in Tokyo: Completed Track C (Malware Analysis).
Media Coverage: Featured on the school website — Youngest to Pass the Information Processing Security Support Specialist Examination—Aiming to Contribute to Society through Cybersecurity.

Period	Details
2024/03	Graduated from Rikkyo Niiza Junior High School / Received Honors Award
2024/04–Present	Rikkyo Niiza Senior High School
2024/07–Present	Ricerca Security, Inc. — Part-time Security Researcher
2025/04–Present	SECCON Beginners — Organizing Committee