activity
20212026
most citedLabel-Only Model Inversion Attacks via Boundary Repulsion

3 citations · 7 across the 11 of their papers we have counts for

collaborators

12 papers

cs.CL2026

Privacy-Preserving Text Sanitization for Distributed Agents Collaboration via Disentangled Representations

Xuan Liu, Hefeng Zhou, Sicheng Chen +6

When distributed agents exchange text across organizational boundaries, privacy leakage arises not only from explicit identifiers but also from distributional signatures such as fo…

cs.LG2025

Just Enough Shifts: Mitigating Over-Refusal in Aligned Language Models with Targeted Representation Fine-Tuning

Mahavir Dabas, Si Chen, Charles Fleming +2

Safety alignment is crucial for large language models (LLMs) to resist malicious instructions but often results in over-refusals, where benign prompts are unnecessarily rejected, i…

cs.AI2025

Strategize Globally, Adapt Locally: A Multi-Turn Red Teaming Agent with Dual-Level Learning

Si Chen, Xiao Yu, Ninareh Mehrabi +3

The exploitation of large language models (LLMs) for malicious purposes poses significant security risks as these models become more powerful and widespread. While most existing re…

cs.LG2024

AutoScale: Scale-Aware Data Mixing for Pre-Training LLMs

Feiyang Kang, Yifan Sun, Bingbing Wen +4

Domain reweighting is an emerging research area aimed at adjusting the relative weights of different data sources to improve the effectiveness and efficiency of LLM pre-training. W…

cs.CL2024

FASTTRACK: Fast and Accurate Fact Tracing for LLMs

Si Chen, Feiyang Kang, Ning Yu +1

Fact tracing seeks to identify specific training examples that serve as the knowledge source for a given query. Existing approaches to fact tracing rely on assessing the similarity…

cs.LG2023

Learning to Rank for Active Learning via Multi-Task Bilevel Optimization

Zixin Ding, Si Chen, Ruoxi Jia +1

Active learning is a promising paradigm to reduce the labeling cost by strategically requesting labels to improve model performance. However, existing active learning methods often…

cs.CV2022★ 1 cited

Turning a Curse into a Blessing: Enabling In-Distribution-Data-Free Backdoor Removal via Stabilized Model Inversion

Si Chen, Yi Zeng, Jiachen T. Wang +5

Many backdoor removal techniques in machine learning models require clean in-distribution data, which may not always be available due to proprietary datasets. Model inversion techn…

cs.CL2022

Just Fine-tune Twice: Selective Differential Privacy for Large Language Models

Weiyan Shi, Ryan Shea, Si Chen +3

Protecting large language models from privacy leakage is becoming increasingly crucial with their wide adoption in real-world products. Yet applying differential privacy (DP), a ca…

cs.LG2022★ 3 cited

Label-Only Model Inversion Attacks via Boundary Repulsion

Mostafa Kahla, Si Chen, Hoang Anh Just +1

Recent studies show that the state-of-the-art deep neural networks are vulnerable to model inversion attacks, in which access to a model is abused to reconstruct private training d…

cs.LG2021

ModelPred: A Framework for Predicting Trained Model from Training Data

Yingyan Zeng, Jiachen T. Wang, Si Chen +3

In this work, we propose ModelPred, a framework that helps to understand the impact of changes in training data on a trained model. This is critical for building trust in various s…

cs.LG2021

Zero-Round Active Learning

Si Chen, Tianhao Wang, Ruoxi Jia

Active learning (AL) aims at reducing labeling effort by identifying the most valuable unlabeled data points from a large pool. Traditional AL frameworks have two limitations: Firs…

cs.LG2021★ 3 cited

One-Round Active Learning

Tianhao Wang, Si Chen, Ruoxi Jia

In this work, we initiate the study of one-round active learning, which aims to select a subset of unlabeled data points that achieve the highest model performance after being labe…