Due to the sensitivity of data, Federated Learning (FL) is employed to enable distributed machine learning while safeguarding data privacy and accommodating the requirements of various devices. However, in the context of semidecentralized FL, clients’ communication and training states are dynamic. This variability arises from local training fluctuations, heterogeneous data distributions, and intermittent client participation. Most existing studies primarily focus on stable client states, neglecting the dynamic challenges inherent in real-world scenarios. To tackle this issue, we propose a TRust-Aware clIent scheduLing mechanism called TRAIL, which assesses client states and contributions, enhancing model training efficiency through selective client participation. We focus on a semi-decentralized FL framework where edge servers and clients train a shared global model using unreliable intra-cluster model aggregation and inter-cluster model consensus. First, we propose an adaptive hidden semi-Markov model to estimate clients’ communication states and contributions. Next, we address a client-server association optimization problem to minimize global training loss. Using convergence analysis, we propose a greedy client scheduling algorithm. Finally, our experiments conducted on real-world datasets demonstrate that TRAIL outperforms state-of-the-art baselines, achieving an improvement of 8.7% in test accuracy and a reduction of 15.3% in training loss.

In the real world, the stable operation of a network is usually inseparable from the mutual support of other networks. In such an interdependent network, a node in one layer may depend on multiple nodes in another layer, forming a complex one-to-many dependence relationship. Meanwhile, there may also be higher-order interactions between multiple nodes within a layer, which increase the connectivity within the layer. Interlayer dependencies and intralayer connectivity may become key factors affecting network reliability, because failures within a layer will propagate to another layer through dependencies, and the cascading effects within and between layers may trigger catastrophic network collapse. However, existing research on one-to-many interdependence often neglects intralayer higher-order structures and lacks a unified theoretical framework for interlayer dependencies. Moreover, current research on interdependent higher-order networks typically assumes idealized one-to-one interlayer dependencies, which does not reflect the complexity of real-world systems. These limitations hinder a comprehensive understanding of how such networks withstand failures. Therefore, this article investigates the robustness of one-to-many interdependent higher-order networks under random attacks. Depending on whether node survival requires at least one dependence edge or multiple dependence edges, we propose four interlayer interdependence conditions and analyze the network’s robustness after cascading failures induced by random attacks. Using percolation theory, we establish a unified theoretical framework that reveals how higher-order interaction structures within intralayers and interlayer coupling parameters affect network reliability and system resilience. In addition, we extend our study to partially interdependent hypergraphs. We validate our theoretical analysis on both synthetic and real-data-based interdependent hypergraphs, offering insights into the optimization of network design for enhanced reliability.

Video action recognition is a technique for automatically determining the category of a video action. It is necessary to design an efficient video action recognition algorithm to predict video labels. This work proposes a video action recognition model based on dual-stream information fusion with attention mechanisms (DSIFAM), which consists of three different sub-modules. First, this proposes an improved keyframe extraction method (IKFE). Based on K-means clustering, this uses convolutional features to calculate the similarity between video frames instead of pixel points. After obtaining preliminary clustering results, the method performs secondary optimization to obtain more representative keyframes. Second, this proposes a video action recognition model based on dual-stream information fusion (DSIF). The method introduces ConvLSTM in the spatial stream and uses P3D instead of the original convolutional network in the temporal stream, which can better extract spatial-temporal information and improve the classification performance. Third, this designs a multi-scale attention mechanism (MSAM) to enhance the feature extraction stage and obtain higher quality classification features. The resulting features are more prominent and have stronger representation capabilities. Finally, this work conducts systematic experiments on different datasets, the results verify the superiority of DSIFAM for video action recognition.

Hierarchical Federated Learning (HFL) improves the scalability and communication efficiency of the system and achieves load balancing at each level. Incentive mechanisms enhance participant motivation and optimize resource allocation for HFL. However, existing mechanisms mainly focus on maximizing individual utility from the quantity of client data while neglecting to optimize social utility from the learning quality perspective. Meanwhile, strategic behavior and heterogeneous devices can significantly degrade the performance of incentive mechanisms. To this end, we propose a quality-aware incentive mechanism (QAIM) for HFL to improve training efficiency. Specifically, we first systematically evaluate the learning quality of clients based on their training loss and historical records, which allows us to recruit high-quality clients for model updating selectively. Then, we model the cloud-edge-end interaction and cooperation as a three-layer Stackelberg game to analyze the strategies of participants and utilize carefully designed algorithms to derive the solution of the unique Stackelberg Equilibrium (SE). Through the Pareto improvement of client association modeled as a coalition game, we can maximize social utility. Experimental results on both synthetic and real-world datasets demonstrate that our QAIM outperforms the state-of-the-art baselines, with an average increase in accuracy and social utility of 17% and 45%, respectively.

Designing a query-efficient attack strategy to generate high-quality adversarial examples under the hard-label black-box setting is a fundamental yet challenging problem, especially in natural language processing (NLP). The process of searching for adversarial examples has many uncertainties (e.g., an unknown impact on the target model's prediction of the added perturbation) when confidence scores cannot be accessed, which must be compensated for with a large number of queries. To address this issue, we propose TextCheater, a decision-based metaheuristic search method that performs a query-efficient textual adversarial attack task by prohibiting invalid searches. The strategies of multiple initialization points and Tabu search are also introduced to keep the search process from falling into a local optimum. We apply our approach to three state-of-the-art language models (i.e., BERT, wordLSTM, and wordCNN) across six benchmark datasets and eight real-world commercial sentiment analysis platforms/models. Furthermore, we evaluate the Robustly optimized BERT pretraining Approach (RoBERTa) and models that enhance their robustness by adversarial training on toxicity detection and text classification tasks. The results demonstrate that our method minimizes the number of queries required for crafting plausible adversarial text while outperforming existing attack methods in the attack success rate, fluency of output sentences, and similarity between the original text and its adversary.

The rich semantic information in Control Flow Graphs (CFGs) of executable programs has made Graph Neural Networks (GNNs) a key focus for malware detection. However, existing CFG-based detection techniques face limitations in node feature extraction, such as information loss, neglect of execution sequence information, and redundancy in representation vectors. These limitations compromise the balance between high efficiency and precision when training detectors. Addressing this, we introduce an innovative Malware CFG Node Embedding (MalGNE) method. This approach utilizes a novel instruction encoding rule to address the Out-Of-Vocabulary(OOV) problem, generates high-quality initial vectors. Then, it employs aggregation layer and sequence layer to extract node aggregation feature and execution sequence feature, in conjunction with GNNs to develop a pre-trained node embedding model. The model maps the semantic information of node assembly instruction sequences into a compact, low-dimensional continuous space, ensuring high-quality feature extraction, and enhancing the performance and efficiency of the detector. We trained the MalGNE model using the BIG 2015 dataset and validated MalGNE-enhanced detector on the SOREL-20M and BODMAS datasets. MalGNE-enhanced detector demonstrates outstanding performance and efficiency in low-dimensional spaces, especially when the dimensionality of the node feature vector is reduced to 16. MalGNE-enhanced detector not only maintains a high detection accuracy of 95.49%. sacrificing only about 1.7% of accuracy to save approximately 73% of training time compared to 128 dimensions.

Generative adversarial networks (GANs) have been widely used for creating diverse data such as images, audio, and videos. However, as the training data of GANs often contain sensitive information, they are vulnerable to privacy attacks on the training dataset, such as membership inference attacks (MIAs). To improve the resistance of GANs to MIA while ensuring their performance, we design a novel GAN framework PGAN-KD (member Privacy protection of GANs based on Knowledge Distillation). PGAN-KD prevents the discriminator from leaking membership information of the training data by introducing knowledge distillation and gradient clipping. Specifically, it adopts an extra teacher discriminator to distilling knowledge and then transfer it to a student discriminator, and thereby isolating the attacker from indirectly obtaining private information through the generator. In addition, the teacher discriminator prevents itself from MIAs through gradient clipping. To evaluate the performance of PGAN-KD, we conducted experiments on both real and simulated datasets. The results indicate that PGAN-KD achieves a 7.8% improvement in privacy protection levels while maintaining similar generation performance with the baselines.