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Kui Ren

37 accepted papers

2026

Eguard: Defending LLM Embeddings Against Inversion Attacks via Text Mutual Information Optimization

AAAI 2026technical

While text embeddings enable efficient semantic processing in LLMs, they remain vulnerable to inversion attacks that reconstruct sensitive original text. However, current defense methods typically treat text embeddings from the feature level independently, ignoring the exploitation of the mutual rel

Cited by 0SourcePDFScholar
2026

Explainable Token-level Noise Filtering for LLM Fine-tuning Datasets

ICLR 2026poster

Large Language Models (LLMs) have seen remarkable advancements, achieving state-of-the-art results in diverse applications. Fine-tuning, an important step for adapting LLMs to specific downstream tasks, typically involves further training on corresponding datasets. However, a fundamental discrepancy…

Cited by 0SourceScholar
2026

FlowHijack: A Dynamics-Aware Backdoor Attack on Flow-Matching Vision-Language-Action Models

CVPR 2026

Vision-Language-Action (VLA) models are emerging as a cornerstone for robotics, with flow-matching policies like \pi_0 showing great promise in generating smooth, continuous actions. As these models advance, their unique action generation mechanism--the vector field dynamics--presents a critical yet

Cited by 0SourceScholar
2026

HyperPotter: Spell the Charm of High-Order Interactions in Audio Deepfake Detection

ICML 2026poster

Advances in AIGC technologies have enabled the synthesis of highly realistic audio deepfakes capable of deceiving human auditory perception. Although numerous audio deepfake detection (ADD) methods have been developed, most rely on local temporal/spectral features or pairwise relations, overlooking …

Cited by 0SourceScholar
2026

JANUS: A Lightweight Framework for Jailbreaking Text-to-Image Models via Distribution Optimization

CVPR 2026

Text-to-image (T2I) models such as Stable Diffusion and DALLE remain susceptible to generating harmful or Not-Safe-For-Work (NSFW) content under jailbreak attacks despite deployed safety filters. Existing jailbreak attacks either rely on proxy-loss optimization instead of the true end-to-end objecti

Cited by 0SourcecodeScholar
2026

MAJIC: Markovian Adaptive Jailbreaking via Iterative Composition of Diverse Innovative Strategies

AAAI 2026technical

Large Language Models (LLMs) have exhibited remarkable capabilities but remain vulnerable to jailbreaking attacks, which can elicit harmful content from the models by manipulating the input prompts. Existing black-box jailbreaking techniques primarily rely on static prompts crafted with a single, no

Cited by 0SourcePDFScholar
2026

SpatialJB: How Text Distribution Art Becomes The "Jailbreak Key" for LLM Guardrails

ICML 2026poster

While Large Language Models (LLMs) have achieved remarkable success across diverse tasks, they remain vulnerable to jailbreak attacks, which pose significant risks to their secure deployment. Current safetymechanisms primarily rely on output guardrails to filter harmful outputs, yet these defenses a…

Cited by 0SourceScholar
2025

DataSIR: A Benchmark Dataset for Sensitive Information Recognition

NeurIPS 2025poster

With the rapid development of artificial intelligence technologies, the demand for training data has surged, exacerbating risks of data leakage. Despite increasing incidents and costs associated with such leaks, data leakage prevention (DLP) technologies lag behind evolving evasion techniques that b…

Cited by 0SourcecodeScholar
2025

FSFM: A Generalizable Face Security Foundation Model via Self-Supervised Facial Representation Learning

CVPR 2025poster

This work asks: with abundant, unlabeled real faces, how to learn a robust and transferable facial representation that boosts various face security tasks with respect to generalization performance? We make the first attempt and propose a self-supervised pretraining framework to learn fundamental rep…

2025

FusionPhys: A Flexible Framework for Fusing Complementary Sensing Modalities in Remote Physiological Measurement

ICCV 2025poster

Remote physiological measurement using visible light cameras has emerged as a powerful tool for non-contact health monitoring, yet its reliability degrades under challenging conditions such as low-light environments or diverse skin tones. These limitations have motivated the exploration of alternati…

2025

Harnessing Frequency Spectrum Insights for Image Copyright Protection Against Diffusion Models

CVPR 2025poster

Diffusion models have achieved remarkable success in novel view synthesis, but their reliance on large, diverse, and often untraceable Web datasets has raised pressing concerns about image copyright protection. Current methods fall short in reliably identifying unauthorized image use, as they strugg…

2025

Mitigating Social Bias in Large Language Models: A Multi-Objective Approach Within a Multi-Agent Framework

AAAI 2025technical

Natural language processing (NLP) has seen remarkable advancements with the development of large language models (LLMs). Despite these advancements, LLMs often produce socially biased outputs. Recent studies have mainly addressed this problem by prompting LLMs to behave ethically, but this approach…

2025

REFINE: Inversion-Free Backdoor Defense via Model Reprogramming

ICLR 2025poster

Backdoor attacks on deep neural networks (DNNs) have emerged as a significant security threat, allowing adversaries to implant hidden malicious behaviors during the model training phase. Pre-processing-based defense, which is one of the most important defense paradigms, typically focuses on input tr…

Cited by 2SourcePDFScholar
2025

Robust Representation Consistency Model via Contrastive Denoising

ICLR 2025poster

Robustness is essential for deep neural networks, especially in security-sensitive applications. To this end, randomized smoothing provides theoretical guarantees for certifying robustness against adversarial perturbations. Recently, diffusion models have been successfully employed for randomized sm…

2025

Taught Well Learned Ill: Towards Distillation-conditional Backdoor Attack

NeurIPS 2025poster

Knowledge distillation (KD) is a vital technique for deploying deep neural networks (DNNs) on resource-constrained devices by transferring knowledge from large teacher models to lightweight student models. While teacher models from third-party platforms may undergo security verification (e.g., backd…

Cited by 0SourcecodeScholar
2025

Textual Unlearning Gives a False Sense of Unlearning

ICML 2025poster

Language Models (LMs) are prone to ''memorizing'' training data, including substantial sensitive user information. To mitigate privacy risks and safeguard the right to be forgotten, machine unlearning has emerged as a promising approach for enabling LMs to efficiently ''forget'' specific texts. Howe…

Cited by 5SourcePDFScholar
2025

WMCopier: Forging Invisible Watermarks on Arbitrary Images

NeurIPS 2025poster

Invisible Image Watermarking is crucial for ensuring content provenance and accountability in generative AI. While Gen-AI providers are increasingly integrating invisible watermarking systems, the robustness of these schemes against forgery attacks remains poorly characterized. This is critical, as…

Cited by 0SourcecodeScholar
2024

Exposing the Deception: Uncovering More Forgery Clues for Deepfake Detection

AAAI 2024technical

Deepfake technology has given rise to a spectrum of novel and compelling applications. Unfortunately, the widespread proliferation of high-fidelity fake videos has led to pervasive confusion and deception, shattering our faith that seeing is believing. One aspect that has been overlooked so far is t…

2024

Self-Para-Consistency: Improving Reasoning Tasks at Low Cost for Large Language Models

ACL 2024findings

Recently, the self-consistency decoding strategy has shown the ability to improve performance for complex reasoning tasks with large language models (LLMs). However, the costs may be high because the sampling process of the strategy generates some low-probability text, resulting in low-quality reaso…

Cited by 5SourcePDFScholar
2024

Towards Reliable and Efficient Backdoor Trigger Inversion via Decoupling Benign Features

ICLR 2024spotlight

Recent studies revealed that using third-party models may lead to backdoor threats, where adversaries can maliciously manipulate model predictions based on backdoors implanted during model training. Arguably, backdoor trigger inversion (BTI), which generates trigger patterns of given benign samples…

Cited by 31SourcePDFScholar
2023

A Large-Scale Pretrained Deep Model for Phishing URL Detection

ICASSP 2023accepted

Phishing attacks have always been a security issue that has attracted great attention in the cyber security community. Recently, the famous pre-trained models is being used as an anti-phishing solution. However, existing studies either simply transfer models pre-trained on text to phishing detection…

Cited by 0SourceScholar
2023

ANetQA: A Large-Scale Benchmark for Fine-Grained Compositional Reasoning Over Untrimmed Videos

CVPR 2023poster

Building benchmarks to systemically analyze different capabilities of video question answering (VideoQA) models is challenging yet crucial. Existing benchmarks often use non-compositional simple questions and suffer from language biases, making it difficult to diagnose model weaknesses incisively. A…

2023

Action Recognition with Multi-stream Motion Modeling and Mutual Information Maximization

IJCAI 2023poster

Action recognition has long been a fundamental and intriguing problem in artificial intelligence. The task is challenging due to the high dimensionality nature of an action, as well as the subtle motion details to be considered. Current state-of-the-art approaches typically learn from articulated mo…

2023

CAPP-130: A Corpus of Chinese Application Privacy Policy Summarization and Interpretation

NeurIPS 2023poster

A privacy policy serves as an online internet protocol crafted by service providers, which details how service providers collect, process, store, manage, and use personal information when users engage with applications. However, these privacy policies are often filled with technobabble and legalese,…

2023

Certified Minimax Unlearning with Generalization Rates and Deletion Capacity

NeurIPS 2023poster

We study the problem of $(\epsilon,\delta)$-certified machine unlearning for minimax models. Most of the existing works focus on unlearning from standard statistical learning models that have a single variable and their unlearning steps hinge on the direct Hessian-based conventional Newton update. W…

Cited by 23SourcePDFScholar
2023

Counterfactual-based Saliency Map: Towards Visual Contrastive Explanations for Neural Networks

ICCV 2023poster

Explaining deep models in a human-understandable way has been explored by many works that mostly explain why an input causes a corresponding prediction (ie., Why P?). However, seldom they could handle those more complex causal questions like "why P rather than Q?" and "why one is P while another is…

Cited by 9PDFScholar
2023

Privacy-Preserving Adversarial Facial Features

CVPR 2023poster

Face recognition service providers protect face privacy by extracting compact and discriminative facial features (representations) from images, and storing the facial features for real-time recognition. However, such features can still be exploited to recover the appearance of the original face by b…

Cited by 22SourcePDFScholar
2023

Purifier: Defending Data Inference Attacks via Transforming Confidence Scores

AAAI 2023technical

Neural networks are susceptible to data inference attacks such as the membership inference attack, the adversarial model inversion attack and the attribute inference attack, where the attacker could infer useful information such as the membership, the reconstruction or the sensitive attributes of a…

Cited by 19SourcePDFScholar
2023

Shift to Your Device: Data Augmentation for Device-Independent Speaker Verification Anti-Spoofing

ICASSP 2023accepted

This paper proposes a novel Deconvolution-enhanced data Augmentation method, DeAug, for ultrasonic-based speaker verification anti-spoofing systems to detect the liveness of voice sources in physical access, which aims to improve the performance of liveness detection on unseen devices where no data…

Cited by 0SourceScholar
2023

Towards Fairness-aware Adversarial Network Pruning

ICCV 2023poster

Network pruning aims to compress models while minimizing loss in accuracy. With the increasing focus on bias in AI systems, the bias inheriting or even magnification nature of traditional network pruning methods has raised a new perspective towards fairness-aware network pruning. Straightforward pru…

Cited by 8PDFScholar
2023

Towards Transferable Targeted Adversarial Examples

CVPR 2023poster

Transferability of adversarial examples is critical for black-box deep learning model attacks. While most existing studies focus on enhancing the transferability of untargeted adversarial attacks, few of them studied how to generate transferable targeted adversarial examples that can mislead models…

2022

A Generalized Weighted Optimization Method for Computational Learning and Inversion

ICLR 2022poster

The generalization capacity of various machine learning models exhibits different phenomena in the under- and over-parameterized regimes. In this paper, we focus on regression models such as feature regression and kernel regression and analyze a generalized weighted least-squares optimization method…

Cited by 3SourcePDFScholar
2022

Backdoor Defense via Decoupling the Training Process

ICLR 2022poster

Recent studies have revealed that deep neural networks (DNNs) are vulnerable to backdoor attacks, where attackers embed hidden backdoors in the DNN model by poisoning a few training samples. The attacked model behaves normally on benign samples, whereas its prediction will be maliciously changed whe…

2022

Fairness-Aware Adversarial Perturbation Towards Bias Mitigation for Deployed Deep Models

CVPR 2022poster

Prioritizing fairness is of central importance in artificial intelligence (AI) systems, especially for those societal applications, e.g., hiring systems should recommend applicants equally from different demographic groups, and risk assessment systems must eliminate racism in criminal justice. Exist…

Cited by 75PDFScholar
2021

Feature Importance-Aware Transferable Adversarial Attacks

ICCV 2021poster

Transferability of adversarial examples is of central importance for attacking an unknown model, which facilitates adversarial attacks in more practical scenarios, e.g., blackbox attacks. Existing transferable attacks tend to craft adversarial examples by indiscriminately distorting features to degr…

Cited by 288PDFcodeScholar