activity
20242026
collaborators

14 papers

cs.LG2026

COMPASS: Membership Inference Attack Against Vision Large Language Models via Adaptive Noise Calibration

Damien Lo, Hong Kyu Lee, Ruixuan Liu +1

Vision large language models (VLLMs) are deployed in privacy-sensitive domains, raising training-data exposure concerns. Existing gray-box membership inference attacks (MIAs) commo…

cs.CR2026

Auditing the Privacy of Synthetic Gene Expression Data: A Unified Weighted-Distance Framework for No-Box Membership Inference

Owen Tucker, Lily Wang, Harutoshi Okumura +2

Synthetic gene expression data is increasingly proposed as a privacy-preserving substitute for controlled-access genomic repositories, but its safety depends on empirical auditing.…

cs.CR2026

PriDyG: Privacy-preserving Dynamic Graph Inference with LLM-GNN Collaboration

Yuyang Xia, Ruixuan Liu, Li Xiong

Graph inference over relational data can expose sensitive edge information, and this risk becomes more severe in dynamic graphs, where repeated model updates cause privacy loss to…

cs.CR2026

Beyond Indistinguishability: Measuring Extraction Risk in LLM APIs

Ruixuan Liu, David Evans, Li Xiong

Indistinguishability properties such as differential privacy bounds or low empirically measured membership inference are widely treated as proxies to show a model is sufficiently p…

cs.DB2026

LLM-Driven Online Aggregation for Unstructured Text Analytics

Chao Hui, Weizheng Lu, Yanjie Gao +3

Large Language Models (LLMs) exhibit strong capabilities in text processing, and recent research has augmented SQL and DataFrame with LLM-powered semantic operators for data analys…

cs.LG2025

FusionDP: Foundation Model-Assisted Differentially Private Learning for Partially Sensitive Features

Linghui Zeng, Ruixuan Liu, Atiquer Rahman Sarkar +3

Ensuring the privacy of sensitive training data is crucial in privacy-preserving machine learning. However, in practical scenarios, privacy protection may be required for only a su…

cs.CR2025

FedSGT: Exact Federated Unlearning via Sequential Group-based Training

Bokang Zhang, Hong Guan, Hong kyu Lee +3

Federated Learning (FL) enables collaborative, privacy-preserving model training, but supporting the "Right to be Forgotten" is especially challenging because data influences the m…

cs.CR2025

SnapAudit: Active Auditing of Differentially Private In-Context Learning via Snapshot-Based Simulation

Yuyang Xia, Ruixuan Liu, Li Xiong

In-context learning (ICL) allows LLMs to adapt to new tasks via a few demonstrations, but those demonstrations may contain sensitive data. Differentially private (DP) ICL mechanism…

cs.CL2025

Direct Token Optimization: A Self-contained Approach to Large Language Model Unlearning

Hong kyu Lee, Ruixuan Liu, Li Xiong

Machine unlearning is an emerging technique that removes the influence of a subset of training data (forget set) from a model without full retraining, with applications including p…

cs.CR2025

UniAud: A Unified Auditing Framework for High Auditing Power and Utility with One Training Run

Ruixuan Liu, Li Xiong

Differentially private (DP) optimization has been widely adopted as a standard approach to provide rigorous privacy guarantees for training datasets. DP auditing verifies whether a…

cs.CR2025

Privacy and Accuracy-Aware AI/ML Model Deduplication

Hong Guan, Lei Yu, Lixi Zhou +5

With the growing adoption of privacy-preserving machine learning algorithms, such as Differentially Private Stochastic Gradient Descent (DP-SGD), training or fine-tuning models on…

cs.LG2025

Tokens for Learning, Tokens for Unlearning: Mitigating Membership Inference Attacks in Large Language Models via Dual-Purpose Training

Toan Tran, Ruixuan Liu, Li Xiong

Large language models (LLMs) have become the backbone of modern natural language processing but pose privacy concerns about leaking sensitive training data. Membership inference at…

cs.CR2024

ExpShield: Safeguarding Web Text from Unauthorized Crawling and LLM Exploitation

Ruixuan Liu, Toan Tran, Tianhao Wang +3

As large language models increasingly memorize web-scraped training content, they risk exposing copyrighted or private information. Existing protections require compliance from cra…

cs.LG2024

Differentially Private Tabular Data Synthesis using Large Language Models

Toan V. Tran, Li Xiong

Synthetic tabular data generation with differential privacy is a crucial problem to enable data sharing with formal privacy. Despite a rich history of methodological research and d…