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

  • Trustworthy Generative ML Models (LLMs, U-MLLMs, Diffusion Models, GANs)
  • Computational Social Science
  • Meta-Study of the ML Security Domain

News

  • [02-2026] Our paper "When Understanding Becomes a Risk: Authenticity and Safety Risks in the Emerging Image Generation Paradigm" got accepted in CVPR'26 (Denver, US).
  • [05-2025] Our paper "JailbreakRadar: Comprehensive Assessment of Jailbreak Attacks Against LLMs" got accepted in ACL'25 (Vienna, Austria).
  • [03-2025] Our paper "Neeko: Model Hijacking Attacks Against GANs" got accepted in ICME'25 (Nantes, France).
  • [03-2025] Our paper "Generated Data with Fake Privacy: Hidden Dangers of Fine-Tuning Large Language Models on Generated Data" got accepted in USENIX Security'25 (Seattle, US).
  • [09-2024] Our paper "Reconstruct Your Previous Conversations! Comprehensively Investigating Privacy Leakage Risks in Conversations with GPT Models" got accepted in EMNLP'24 (Miami, US).
  • [03-2024] Our paper "Games and Beyond: Analyzing the Bullet Chats of Esports Livestreaming" got accepted in ICWSM'24 (Buffalo, US).
  • [09-2023] With the super 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

Teaching

  1. Teaching Assistant

    Uppsala University, IT Department — 2022 Spring

    1DL034 Introduction to Machine Learning
    1TD069 Data Engineering I

Publications

Also find my articles on Google Scholar.

  • 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 Core A*

  • 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

    Paper Website

  • 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 Core A*
    Paper Website

  • Neeko: Model Hijacking Attacks Against Generative Adversarial Networks

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

    ICME'25 Core A
    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 Core A*
    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 Core A*
    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 Core A
    Paper

  • Efficient Resource Scheduling for Distributed Infrastructures Using Negotiation Capabilities

    Junjie Chu, Prashant Singh, Salman Toor

    CLOUD'23 Core B
    Paper

Misc.

Gallery of My Cats

  • Riki
    Riki
  • Jelly
    Jelly
  • Sleeping
    Sleeping

Visited Places