Abstract:Transferable targeted adversarial attacks aim to mislead models into outputting adversary-specified predictions in black-box scenarios. Recent studies have introduced \textit{single-target} generative attacks that train a generator for each target class to generate highly transferable perturbations, resulting in substantial computational overhead when handling multiple classes. \textit{Multi-target} attacks address this by training only one class-conditional generator for multiple classes. However, the generator simply uses class labels as conditions, failing to leverage the rich semantic information of the target class. To this end, we design a \textbf{C}LIP-guided \textbf{G}enerative \textbf{N}etwork with \textbf{C}ross-attention modules (CGNC) to enhance multi-target attacks by incorporating textual knowledge of CLIP into the generator. Extensive experiments demonstrate that CGNC yields significant improvements over previous multi-target generative attacks, e.g., a 21.46\% improvement in success rate from ResNet-152 to DenseNet-121. Moreover, we propose a masked fine-tuning mechanism to further strengthen our method in attacking a single class, which surpasses existing single-target methods.
Abstract:Vision-Language Pre-training (VLP) models trained on large-scale image-text pairs have demonstrated unprecedented capability in many practical applications. However, previous studies have revealed that VLP models are vulnerable to adversarial samples crafted by a malicious adversary. While existing attacks have achieved great success in improving attack effect and transferability, they all focus on instance-specific attacks that generate perturbations for each input sample. In this paper, we show that VLP models can be vulnerable to a new class of universal adversarial perturbation (UAP) for all input samples. Although initially transplanting existing UAP algorithms to perform attacks showed effectiveness in attacking discriminative models, the results were unsatisfactory when applied to VLP models. To this end, we revisit the multimodal alignments in VLP model training and propose the Contrastive-training Perturbation Generator with Cross-modal conditions (C-PGC). Specifically, we first design a generator that incorporates cross-modal information as conditioning input to guide the training. To further exploit cross-modal interactions, we propose to formulate the training objective as a multimodal contrastive learning paradigm based on our constructed positive and negative image-text pairs. By training the conditional generator with the designed loss, we successfully force the adversarial samples to move away from its original area in the VLP model's feature space, and thus essentially enhance the attacks. Extensive experiments show that our method achieves remarkable attack performance across various VLP models and Vision-and-Language (V+L) tasks. Moreover, C-PGC exhibits outstanding black-box transferability and achieves impressive results in fooling prevalent large VLP models including LLaVA and Qwen-VL.
Abstract:Model Inversion (MI) attacks aim to disclose private information about the training data by abusing access to the pre-trained models. These attacks enable adversaries to reconstruct high-fidelity data that closely aligns with the private training data, which has raised significant privacy concerns. Despite the rapid advances in the field, we lack a comprehensive overview of existing MI attacks and defenses. To fill this gap, this paper thoroughly investigates this field and presents a holistic survey. Firstly, our work briefly reviews the traditional MI on machine learning scenarios. We then elaborately analyze and compare numerous recent attacks and defenses on \textbf{D}eep \textbf{N}eural \textbf{N}etworks (DNNs) across multiple modalities and learning tasks.