With the rapid development of Internet of Things (IoT), distributed denial of service (DDoS) attacks become the important security threat of the IoT. Characteristics of IoT, such as large quantities and simple function, which have easily caused the IoT devices or servers to be attacked and be turned into botnets for launching DDoS attacks. In this paper, we use software-defined networking (SDN) to develop moving target defense (MTD) architecture that increases uncertainty because of ever changing attack surface. In addition, we deploy SDN-based honeypots to mimic IoT devices, luring attackers and malwares. Finally, experimental results show that combination of MTD and SDN-based honeypots can effectively hide network asset from scanner and defend against DDoS attacks in IoT.

The security and privacy of a system are urgent issues in achieving secure and efficient learning-based systems. Recent studies have shown that these systems are susceptible to subtle adversarial perturbations applied to inputs. Although these perturbations are difficult for humans to detect, they can easily mislead deep learning classifiers. Noise injection, as a defense mechanism, can offer a provable defense against adversarial attacks by reducing sensitivity to subtle input changes. However, these methods face issues of computational complexity and limited adaptability. We propose a multilayer filter defense model, drawing inspiration from filter-based image denoising techniques. This model inserts a filtering layer after the input layer and before the convolutional layer, and incorporates noise injection techniques during the training process. This model substantially enhances the resilience of image classification systems to adversarial attacks. We also investigated the impact of various filter combinations, filter area sizes, standard deviations, and filter layers on the effectiveness of defense. The experimental results indicate that, across the MNIST, CIFAR10, and CIFAR100 datasets, the multilayer filter defense model achieves the highest average accuracy when employing a double-layer Gaussian filter (filter area size of $3\times 3$, standard deviation of 1). We compared our method with two filter-based defense models, and the experimental results demonstrated that our method attained an average accuracy of 71.9%, effectively enhancing the robustness of the image recognition classifier against adversarial attacks. This method not only performs well on small-scale datasets but also exhibits robustness on large-scale datasets (miniImageNet) and modern models (EfficientNet and WideResNet).

Machine learning systems, particularly in the domain of image recognition, are susceptible to adversarial perturbations applied to input data. These perturbations, while imperceptible to humans, have the capacity to easily deceive deep learning classifiers. Current defense methods for image recognition focus on using diffusion models and their variants. Due to the depth of diffusion models and the large amount of computations generated during each inference process, the GPU and storage performance of the device are extremely high. To address this problem, we propose a new defense-based non-overlapping image compression filter for image recognition classifiers against adversarial attacks. This method inserts a non-overlapping image compression filter before the classifier to make the results of the classifier invariant under subtle changes in images. This method does not weaken the adversarial robustness of the model and can reduce the computational cost during the training process of the image classification model. In addition, our method can be easily integrated with existing image classification training frameworks with only some minor adjustments. We validate our results by performing a series of experiments under three different convolutional neural network architectures (VGG16, ResNet34, and Inception-ResNet-v2) and on different datasets (CIFAR10 and CIFAR100). The experimental results show that under the Inception-ResNet-v2 architecture, our method achieves an average accuracy of up to 81.15% on the CIFAR10 dataset, fully demonstrating its effectiveness in mitigating adversarial attacks. In addition, under the WRN-28-10 architecture, our method achieves not only 91.28% standard accuracy on the CIFAR10 dataset but also 76.46% average robust accuracy. The test experiment on the model training time consumption shows that our defense method has an advantage in time cost, proving that our defense method is a lightweight and efficient defense strategy.