About Me

I am exploring trustworthy artificial intelligence under the close guidance of Prof. Dr. Yang Zhang and Prof. Dr. Michael Backes. I am currently pursuing my Ph.D. at CISPA Helmholtz Center for Information Security, Germany. I hold a Master's degree from Uppsala University, Sweden, and a Bachelor's degree from Shanghai Jiao Tong University, China.

Research Interests

  • Generative Machine Learning
  • Trustworthy Artificial Intelligence

News

  • [08-2026] Our paper JADES: A Universal Framework for Jailbreak Assessment via Decompositional Scoring has been accepted by EMNLP'26 (Budapest, Hungary).
  • [08-2026] Our three papers Behavior Carries Over: An AI Sandbagging Detection Method Inspired by Honest Inertia, RW2Unsafe: Towards More Accurate Real-World Unsafe Generation Evaluation for T2I Models, and GuardrailAgent: An Agentic Framework for Jailbreak Defense have been accepted by EMNLP'26 Findings (Budapest, Hungary).
  • [05-2026] I was recognized as a Gold Reviewer for ICML'26 (Seoul, South Korea).
  • [02-2026] Our paper When Understanding Becomes a Risk: Authenticity and Safety Risks in the Emerging Image Generation Paradigm has been accepted by CVPR'26 (Denver, US).
  • [05-2025] Our paper JailbreakRadar: Comprehensive Assessment of Jailbreak Attacks Against LLMs has been accepted by ACL'25 (Vienna, Austria).
  • [03-2025] Our paper Neeko: Model Hijacking Attacks Against GANs has been accepted by ICME'25 (Nantes, France).
  • [03-2025] Our paper Generated Data with Fake Privacy: Hidden Dangers of Fine-Tuning Large Language Models on Generated Data has been accepted by USENIX Security'25 (Seattle, US).
  • [09-2024] Our paper Reconstruct Your Previous Conversations! Comprehensively Investigating Privacy Leakage Risks in Conversations with GPT Models has been accepted by EMNLP'24 (Miami, US).
  • [03-2024] Our paper Games and Beyond: Analyzing the Bullet Chats of Esports Livestreaming has been accepted by ICWSM'24 (Buffalo, US).
  • [09-2023] With the support of Prof. Dr. Yang Zhang and Prof. Dr. Michael Backes, I successfully passed my Qualifying Exam.
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Resume

Education

  1. Ph.D.

    CISPA Helmholtz Center for Information Security / Saarland University, Germany Nov 2022 — Present

    Advisor: Prof. Dr. Yang Zhang
    Supervisor: Prof. Dr. Michael Backes

  2. M.Sc.

    Uppsala University, Sweden

    Advisor: Prof. Dr. Salman Toor

  3. B.Sc.

    Shanghai Jiao Tong University, China

Experience

  1. Data Engineer (Intern)

    Scaleout, Uppsala, Sweden Nov 2021 — Jan 2022

  2. Data Engineer (Intern)

    Ericsson, Shanghai, China Jun 2021 — Sep 2021

    Mentor: Daniel Chen

  3. Assistant Manager of Product Development (Intern)

    Haitong Securities, Shanghai, China Jun 2016 — Sep 2016

    Mentor: Yuanhua (Inni) Shi

Publications

Also find my articles on Google Scholar.

  • JADES: A Universal Framework for Jailbreak Assessment via Decompositional Scoring

    Junjie Chu, Mingjie Li, Ziqing Yang, Ye Leng, Chenhao Lin, Chao Shen, Michael Backes, Yun Shen, Yang Zhang

    EMNLP'26
    Paper Website

  • Behavior Carries Over: An AI Sandbagging Detection Method Inspired by Honest Inertia

    Junjie Chu, Mingjie Li, Zeyuan Chen, Ye Leng, Yisen Wang, Michael Backes, Yang Zhang

    EMNLP'26 Findings

  • RW2Unsafe: Towards More Accurate Real-World Unsafe Generation Evaluation for T2I Models

    Ye Leng, Junjie Chu, Mingjie Li, Yun Shen, Michael Backes, Yang Zhang

    EMNLP'26 Findings

  • GuardrailAgent: An Agentic Framework for Jailbreak Defense

    Tianze Chang, Junjie Chu, Yixin Wu, Michael Backes, Yang Zhang

    EMNLP'26 Findings

  • When Understanding Becomes a Risk: Authenticity and Safety Risks in the Emerging Image Generation Paradigm

    Ye Leng*, Junjie Chu*, Mingjie Li, Chenhao Lin, Chao Shen, Michael Backes, Yun Shen, Yang Zhang

    * Co-first authors. Selected as CVPR'26 highlight

    CVPR'26
    Paper

  • JailbreakRadar: Comprehensive Assessment of Jailbreak Attacks Against LLMs

    Junjie Chu, Yugeng Liu, Ziqing Yang, Xinyue Shen, Michael Backes, Yang Zhang

    Selected as ACL'25 oral (243/1699 accepted papers)

    ACL'25
    Paper Website

  • Neeko: Model Hijacking Attacks Against Generative Adversarial Networks

    Junjie Chu, Yugeng Liu, Xinlei He, Michael Backes, Yang Zhang, Ahmed Salem

    ICME'25
    Paper PDF

  • Generated Data with Fake Privacy: Hidden Dangers of Fine-Tuning Large Language Models on Generated Data

    Atilla Akkus, Masoud Poorghaffar Aghdam, Mingjie Li, Junjie Chu, Michael Backes, Yang Zhang, Sinem Sav

    USENIX Security'25
    Paper

  • Reconstruct Your Previous Conversations! Comprehensively Investigating Privacy Leakage Risks in Conversations with GPT Models

    Junjie Chu, Zeyang Sha, Michael Backes, Yang Zhang

    Assigned as EMNLP'24 oral

    EMNLP'24
    Paper

  • Games and Beyond: Analyzing the Bullet Chats of Esports Livestreaming

    Yukun Jiang, Xinyue Shen, Rui Wen, Zeyang Sha, Junjie Chu, Yugeng Liu, Michael Backes, Yang Zhang

    ICWSM'24
    Paper

  • Efficient Resource Scheduling for Distributed Infrastructures Using Negotiation Capabilities

    Junjie Chu, Prashant Singh, Salman Toor

    CLOUD'23
    Paper

  • Energy Harvesting of Air-Borne Sound by Using Layered Acoustic Metamaterials

    Jiajie Xu, Xiaole Wang, Junjie Chu, Zhenyu Huang

    ICSV'18
    PDF

Service

Reviewer / Program Committee Member

  1. Conferences

    • 2027: AAAI, SaTML
    • 2026: ACL ARR May/August, ICME, ICML (Gold Reviewer), SaTML
    • 2025: ACL ARR May/July/October, ICME, WWW

  2. Transactions / Journals

    • TDSC, TIFS, TOPS, TOSEM, IEEE Secur. Priv., Neural Netw.

Teaching

  1. 2022-Spring

    Teaching Assistant, Uppsala University, IT Department
    1DL034 Introduction to Machine Learning
    1TD069 Data Engineering I

Misc.

Gallery of My Cats

  • Riki
    Riki
  • Jelly
    Jelly
  • Sleeping
    Sleeping

Visited Places