Woohyuk Choi (최우혁)

I am a M.S. student in CompSec Lab, Department of Electrical and Computer Engineering, Seoul National University. I am advised by Prof. Byoungyoung Lee.

I am interested in security for AI and system security in general. In particular, my research focuses on AI agent security. I designed Prompt Flow Integrity, a system-level mitigation against prompt injection attacks in LLM agents. Building on this, my current research focuses on system-level defenses for web agents.

I am currently seeking internship or visiting researcher opportunities in the areas of system security and AI agent security. If you are interested in collaborating or have opportunities available, please feel free to reach out to me at 00cwooh@snu.ac.kr.

Publications

GHost in the SHELL: A GPU-to-Host Memory Attack and Its Mitigation

Sihyun Roh, Woohyuk Choi, Jaeyoung Chung, Yoochan Lee, Suhwan Song and Byoungyoung Lee
IEEE Symposium on Security and Privacy (SP) 2026 (accepted, to appear)

Prompt Flow Integrity to Prevent Privilege Escalation in LLM Agents

Woohyuk Choi*, Juhee Kim*, and Byoungyoung Lee
arXiv:2503.15547, 2025 (* Equal contribution)

Experience

Internship, Samsung MX (Mobile eXperience), Security Engineering Group

Suwon, Korea, Jan 2024 - Feb 2024