Hi, I'm Yifei.
My research focuses on large language models and agentic systems, with an emphasis on reliability, self-improvement, and efficiency. My broader goal is to build capable and trustworthy AI systems for real-world applications.
Open to research internship opportunities in AI agents, reliability, and AI safety.
Education & research
2026 - Present
University of North Carolina at Chapel Hill
Ph.D. in Computer Science. Advised by Prof. Zhun Deng, working on AI agents, reliability, and AI safety.
2023 - 2025
Carnegie Mellon University
M.Sc. in Information Security, CQPA: 4.0/4.0. Worked with Prof. Steven Wu on AI safety and privacy.
Outstanding Student Services Award - Research Assistant (2025) Presented by the Information Networking Institute.
2019 - 2023
Zhejiang University
B.Eng. in Computer Science and Technology. Worked with Prof. Kai Bu on network security and path validation.
Recent work
ReliabilityCOLM 2026 · Equal contribution
Rubrics as an Attack Surface: Stealthy Preference Drift in LLM Judges
AI PrivacyNeurIPS 2025
Rethinking Exact Unlearning under Exposure: Extracting Forgotten Data under Exact Unlearning in Large Language Models
AI PrivacyTheory and Practice of Differential Privacy 2025
Winning the MIDST Challenge: New Membership Inference Attacks on Diffusion Models for Tabular Data Synthesis
Network SecurityIEEE TDSC 2026
SwiftOracle: Orthogonality-driven Private Multipath Validation
Projects
Carnegie Mellon University · 2025
Membership inference on fine-tuned LLMs
Designed and deployed the first project on membership inference attacks for CMU 18-734/17-731, Foundations of Privacy, including its evaluation pipeline, baselines, codebase, and leaderboard.
Vector Institute MIDST Challenge · 2025
Membership inference for synthetic tabular data
Built stable white-box and black-box attacks for diffusion-based tabular synthesis. Our team placed first across all four competition tracks among 71 participants.
Teaching
Fall 2025
Foundations of Privacy
Teaching Assistant · Carnegie Mellon University · 18-734/17-731
Fall 2024
Fundamentals of Telecommunications Networks
Teaching Assistant · Carnegie Mellon University · 14-740
Let's connect
Interested in research internships and collaborations.
If you are working on AI agents, reliability, or AI safety, I would be glad to hear from you.
ppppyf4534@gmail.com