In recent years, the increasing computational and storage demands of deep steganalysis models have drawn attention to lightweight architectures. While pruning algorithms for image steganalysis networks have been proposed, they often do not apply to networks equipped with mobile inverted bottleneck (MBConv) structures, such as EfficientNet. In this paper, we propose a Squeeze-and-Excitation Attention-based Pruning framework for image steganalysis networks, named SEAP. The method adopts a block-wise structured pruning strategy guided by the SE channel attention mechanism, where unimportant channels within each MBConv block are identified based on SE attention values and soft masks. Since pruning is conducted independently within each MBConv block and the input/output dimensions of the block remain unchanged, potential pruning conflicts across blocks are effectively avoided. In addition, we propose a sparsity regularization mechanism that adaptively adjusts the regularization strength based on the network structure, helping to preserve detection performance. Extensive experimental results demonstrate that the pruned network retains only a small fraction of the original network’s parameters and computational costs while achieving performance comparable to the original unpruned networks.

Anti-forensics seeks to eliminate or conceal traces of tampering artifacts. Typically, anti-forensic methods are designed to deceive binary detectors and persuade them to misjudge the authenticity of an image. However, to the best of our knowledge, no attempts have been made to deceive forgery detectors at the pixel level and mis-locate forged regions. Traditional adversarial attack methods cannot be directly used against forgery localization due to the following defects: 1) they tend to just naively induce the target forensic models to flip their pixel-level pristine or forged decisions; 2) their anti-forensics performance tends to be severely degraded when faced with the unseen forensic models; 3) they lose validity once the target forensic models are retrained with the anti-forensics images generated by them. To tackle the three defects, we propose SEAR (Self-supErvised Anti-foRensics), a novel self-supervised and adversarial training algorithm that effectively trains deep-learning anti-forensic models against forgery localization. SEAR sets a pretext task to reconstruct perturbation for self-supervised learning. In adversarial training, SEAR employs a forgery localization model as a supervisor to explore tampering features and constructs a deep-learning concealer to erase corresponding traces. We have conducted large-scale experiments across diverse datasets. The experimental results demonstrate that, through the combination of self-supervised learning and adversarial learning, SEAR successfully deceives the state-of-the-art forgery localization methods, as well as tackle the three defects regarding traditional adversarial attack methods mentioned above.

The steganalysis of JPEG images is a crucial area of research. Deep-learning based steganalysis methods have achieved superior detection performance. All methods for JPEG steganalysis rely on residual networks. Although the incorporation of residual connections has enhanced detection performance, it has also led to a notable increase in computational complexity. Furthermore, most of these methods are not complete end-to-end models. In their approaches, traditional hand-crafted filters are employed for image preprocessing. To avoid relying on residual connections and prior knowledge, we propose an end-to-end VGG-style ConvNet. During training, the model utilizes a multi-branch architecture, while it is transformed into a VGG-style ConvNet through structural reparameterization during inference. We conduct extensive experiments on ALASKA KAGGLE dataset and ALASKA II dataset, demonstrating that the proposed method achieves state-of-the-art results in the JPEG domain comparable to other CNN-based steganalyzers such as UCNet and EfficientNet, with clearly better convergence capacity and lower model complexity.

This paper presents a summary of the DeepFake Game Competition (DFGC) 20211. DeepFake technology is developing fast, and realistic face-swaps are increasingly deceiving and hard to detect. At the same time, DeepFake detection methods are also improving. There is a two-party game between DeepFake creators and detectors. This competition provides a common platform for benchmarking the adversarial game between current state-of-the-art DeepFake creation and detection methods. In this paper, we present the organization, results and top solutions of this competition and also share our insights obtained during this event. We also release the DFGC-21 testing dataset collected from our participants to further benefit the research community2.