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Shiqing Ma

33 accepted papers

2026

Bias Similarity Measurement: A Black-Box Audit of Fairness Across LLMs

ICLR 2026poster

Large Language Models (LLMs) reproduce social biases, yet prevailing evaluations score models in isolation, obscuring how biases persist across families and releases. We introduce Bias Similarity Measurement (BSM), which treats fairness as a relational property between models, unifying scalar, distr…

Cited by 2SourcecodeScholar
2026

From Chaos to Clarity: A Knowledge Graph-Driven Audit Dataset Generation Framework for LLM Unlearning

AAAI 2026technical

Recently LLMs have faced increasing demands to selectively remove specific information through Machine Unlearning. While evaluating unlearning effectiveness is crucial, existing benchmarks suffer from fundamental limitations in audit dataset generation from unstructured corpora. We identify two crit

Cited by 0SourcePDFScholar
2026

PROMPTMINER: Black-Box Prompt Stealing against Text-to-Image Generative Models via Reinforcement Learning and VLM-Guided Optimization

CVPR 2026

Text-to-image (T2I) generative models such as Stable Diffusion and FLUX can synthesize realistic, high-quality images directly from textual prompts. The resulting image quality depends critically on well-crafted prompts that specify both subjects and stylistic modifiers, which have become valuable d

Cited by 0SourcecodeScholar
2025

An Optimizable Suffix Is Worth A Thousand Templates: Efficient Black-box Jailbreaking without Affirmative Phrases via LLM as Optimizer

NAACL 2025findings

Despite prior safety alignment efforts, LLMs can still generate harmful and unethical content when subjected to jailbreaking attacks. Existing jailbreaking methods fall into two main categories: template-based and optimization-based methods. The former requires significant manual effort and domain k…

2025

Continuous Concepts Removal in Text-to-image Diffusion Models

NeurIPS 2025poster

Text-to-image diffusion models have shown an impressive ability to generate high-quality images from input textual descriptions/prompts. However, concerns have been raised about the potential for these models to create content that infringes on copyrights or depicts disturbing subject matter. Removi…

Cited by 0SourcecodeScholar
2025

Data-centric NLP Backdoor Defense from the Lens of Memorization

NAACL 2025findings

Backdoor attack is a severe threat to the trustworthiness of DNN-based language models. In this paper, we first extend the definition of memorization of language models from sample-wise to more fine-grained sentence element-wise (e.g., word, phrase, structure, and style), and then point out that lan…

Cited by 3SourcePDFScholar
2025

Invisible Backdoor Attack against Self-supervised Learning

CVPR 2025poster

Self-supervised learning (SSL) models are vulnerable to backdoor attacks. Existing backdoor attacks that are effective in SSL often involve noticeable triggers, like colored patches or visible noise, which are vulnerable to human inspection. This paper proposes an imperceptible and effective backdoo…

2025

MLLM-as-a-Judge for Image Safety without Human Labeling

CVPR 2025highlight

Image content safety has become a significant challenge with the rise of visual media on online platforms. Meanwhile, in the age of AI-generated content (AIGC), many image generation models are capable of producing harmful content, such as images containing sexual or violent material. Thus, it becom…

Cited by 2SourcePDFScholar
2025

STAFF: Speculative Coreset Selection for Task-Specific Fine-tuning

ICLR 2025poster

Task-specific fine-tuning is essential for the deployment of large language models (LLMs), but it requires significant computational resources and time. Existing solutions have proposed coreset selection methods to improve data efficiency and reduce model training overhead, but they still have limit…

Cited by 2SourcePDFScholar
2025

The Invisible Hand: Unveiling Provider Bias in Large Language Models for Code Generation

ACL 2025long

Large Language Models (LLMs) have emerged as the new recommendation engines, surpassing traditional methods in both capability and scope, particularly in code generation. In this paper, we reveal a novel **provider bias** in LLMs: without explicit directives, these models show systematic preferences…

2025

Tightening Robustness Verification of MaxPool-based Neural Networks via Minimizing the Over-Approximation Zone

CVPR 2025poster

The robustness of neural network classifiers is important in the safety-critical domain and can be quantified by robustness verification. At present, efficient and scalable verification techniques are always sound but incomplete, and thus, the improvement of verified robustness results is the key cr…

2025

Token-Budget-Aware LLM Reasoning

ACL 2025finding

Reasoning is critical for large language models (LLMs) to excel in a wide range of tasks. While methods like Chain-of-Thought (CoT) reasoning and enhance LLM performance by decomposing problems into intermediate steps, they also incur significant overhead in token usage, leading to increased costs.…

2024

DIAGNOSIS: Detecting Unauthorized Data Usages in Text-to-image Diffusion Models

ICLR 2024poster

Recent text-to-image diffusion models have shown surprising performance in generating high-quality images. However, concerns have arisen regarding the unauthorized data usage during the training or fine-tuning process. One example is when a model trainer collects a set of images created by a particu…

2024

Elijah: Eliminating Backdoors Injected in Diffusion Models via Distribution Shift

AAAI 2024technical

Diffusion models (DM) have become state-of-the-art generative models because of their capability of generating high-quality images from noises without adversarial training. However, they are vulnerable to backdoor attacks as reported by recent studies. When a data input (e.g., some Gaussian noise)…

2024

How to Trace Latent Generative Model Generated Images without Artificial Watermark?

ICML 2024poster

Latent generative models (e.g., Stable Diffusion) have become more and more popular, but concerns have arisen regarding potential misuse related to images generated by these models. It is, therefore, necessary to analyze the origin of images by inferring if a particular image was generated by a spec…

2024

LOTUS: Evasive and Resilient Backdoor Attacks through Sub-Partitioning

CVPR 2024poster

Backdoor attack poses a significant security threat to Deep Learning applications. Existing attacks are often not evasive to established backdoor detection techniques. This susceptibility primarily stems from the fact that these attacks typically leverage a universal trigger pattern or transformatio…

2024

Towards General Robustness Verification of MaxPool-based Convolutional Neural Networks via Tightening Linear Approximation

CVPR 2024poster

The robustness of convolutional neural networks (CNNs) is vital to modern AI-driven systems. It can be quantified by formal verification by providing a certified lower bound within which any perturbation does not alter the original input's classification result. It is challenging due to nonlinear co…

2024

UNIT: Backdoor Mitigation via Automated Neural Distribution Tightening

ECCV 2024poster

"Deep neural networks (DNNs) have demonstrated effectiveness in various fields. However, DNNs are vulnerable to backdoor attacks, which inject a unique pattern, called trigger, into the input to cause misclassification to an attack-chosen target label. While existing works have proposed various meth…

2023

Detecting Backdoors in Pre-Trained Encoders

CVPR 2023poster

Self-supervised learning in computer vision trains on unlabeled data, such as images or (image, text) pairs, to obtain an image encoder that learns high-quality embeddings for input data. Emerging backdoor attacks towards encoders expose crucial vulnerabilities of self-supervised learning, since dow…

2023

Django: Detecting Trojans in Object Detection Models via Gaussian Focus Calibration

NeurIPS 2023poster

Object detection models are vulnerable to backdoor or trojan attacks, where an attacker can inject malicious triggers into the model, leading to altered behavior during inference. As a defense mechanism, trigger inversion leverages optimization to reverse-engineer triggers and identify compromised m…

2023

FLIP: A Provable Defense Framework for Backdoor Mitigation in Federated Learning

ICLR 2023poster

Federated Learning (FL) is a distributed learning paradigm that enables different parties to train a model together for high quality and strong privacy protection. In this scenario, individual participants may get compromised and perform backdoor attacks by poisoning the data (or gradients). Existin…

2023

NOTABLE: Transferable Backdoor Attacks Against Prompt-based NLP Models

ACL 2023long

Prompt-based learning is vulnerable to backdoor attacks. Existing backdoor attacks against prompt-based models consider injecting backdoors into the entire embedding layers or word embedding vectors. Such attacks can be easily affected by retraining on downstream tasks and with different prompting s…

2023

Where Did I Come From? Origin Attribution of AI-Generated Images

NeurIPS 2023poster

Image generation techniques have been gaining increasing attention recently, but concerns have been raised about the potential misuse and intellectual property (IP) infringement associated with image generation models. It is, therefore, necessary to analyze the origin of images by inferring if a spe…

2022

Better Trigger Inversion Optimization in Backdoor Scanning

CVPR 2022oral

Backdoor attacks aim to cause misclassification of a subject model by stamping a trigger to inputs. Backdoors could be injected through malicious training and naturally exist. Deriving backdoor trigger for a subject model is critical to both attack and defense. A popular trigger inversion method is…

Cited by 104PDFScholar
2022

BppAttack: Stealthy and Efficient Trojan Attacks Against Deep Neural Networks via Image Quantization and Contrastive Adversarial Learning

CVPR 2022poster

Deep neural networks are vulnerable to Trojan attacks. Existing attacks use visible patterns (e.g., a patch or image transformations) as triggers, which are vulnerable to human inspection. In this paper, we propose stealthy and efficient Trojan attacks, BppAttack. Based on existing biology literatur…

Cited by 120PDFcodeScholar
2022

Complex Backdoor Detection by Symmetric Feature Differencing

CVPR 2022poster

Many existing backdoor scanners work by finding a small and fixed trigger. However, advanced attacks have large and pervasive triggers, rendering existing scanners less effective. We develop a new detection method. It first uses a trigger inversion technique to generate triggers, namely, universal i…

Cited by 64PDFcodeScholar
2022

Constrained Optimization with Dynamic Bound-scaling for Effective NLP Backdoor Defense

ICML 2022spotlight

Modern language models are vulnerable to backdoor attacks. An injected malicious token sequence (i.e., a trigger) can cause the compromised model to misbehave, raising security concerns. Trigger inversion is a widely-used technique for scanning backdoors in vision models. It can- not be directly app…

2022

Rethinking the Reverse-engineering of Trojan Triggers

NeurIPS 2022accept

Deep Neural Networks are vulnerable to Trojan (or backdoor) attacks. Reverse-engineering methods can reconstruct the trigger and thus identify affected models. Existing reverse-engineering methods only consider input space constraints, e.g., trigger size in the input space. Expressly, they assume th…

2022

Training with More Confidence: Mitigating Injected and Natural Backdoors During Training

NeurIPS 2022accept

The backdoor or Trojan attack is a severe threat to deep neural networks (DNNs). Researchers find that DNNs trained on benign data and settings can also learn backdoor behaviors, which is known as the natural backdoor. Existing works on anti-backdoor learning are based on weak observations that the…

2021

Backdoor Scanning for Deep Neural Networks through K-Arm Optimization

ICML 2021spotlight

Back-door attack poses a severe threat to deep learning systems. It injects hidden malicious behaviors to a model such that any input stamped with a special pattern can trigger such behaviors. Detecting back-door is hence of pressing need. Many existing defense techniques use optimization to generat…

2021

Deep Feature Space Trojan Attack of Neural Networks by Controlled Detoxification

AAAI 2021technical

Trojan (backdoor) attack is a form of adversarial attack on deep neural networks where the attacker provides victims with a model trained/retrained on malicious data. The backdoor can be activated when a normal input is stamped with a certain pattern called trigger, causing misclassification. Many e…

2018

Attacks Meet Interpretability: Attribute-steered Detection of Adversarial Samples

NeurIPS 2018spotlight

Adversarial sample attacks perturb benign inputs to induce DNN misbehaviors. Recent research has demonstrated the widespread presence and the devastating consequences of such attacks. Existing defense techniques either assume prior knowledge of specific attacks or may not work well on complex models…