Website fingerprinting (WF) attacks can reveal information about the websites users browse by de-anonymizing encrypted traffic. Traditional website fingerprinting attack models, focusing solely on a single spatial feature, are inefficient regarding training time. When confronted with the concept drift problem, they suffer from a sharp drop in attack accuracy within a short period due to their reliance on extensive, outdated training data. To address the above problems, this paper proposes a parallel website fingerprinting attack (APWF) that incorporates an attention mechanism, which consists of an attack model and a fine-tuning method. Among them, the APWF model innovatively adopts a parallel structure, fusing temporal features related to both the front and back of the fingerprint sequence, along with spatial features captured through channel attention enhancement, to enhance the accuracy of the attack. Meanwhile, the APWF method introduces isomorphic migration learning and adjusts the model by freezing the optimal model weights and fine-tuning the parameters so that only a small number of the target, samples are needed to adapt to web page changes. A series of experiments show that the attack model can achieve 83% accuracy with the help of only 10 samples per category, which is a 30% improvement over the traditional attack model. Compared to comparative modeling, APWF improves accuracy while reducing time costs. After further fine-tuning the freezing model, the method in this paper can maintain the accuracy at 92.4% in the scenario of 56 days between the training data and the target data, which is only 4% less loss compared to the instant attack, significantly improving the robustness and accuracy of the model in coping with conceptual drift.
以Gunther Kress和Theo van Leeuwen的视觉语法理论为分析框架,通过对南京旅游英文官网的案例研究,分析旅游网站多模态话语的再现意义、互动意义和构图意义。研究发现,南京旅游英文网站使用大量图片视觉符号资源构建意义,图片符号与文字符号协同作用,对观看者产生视觉上的冲击,达到良好的宣传效果。不足之处在于,叙事再现图片占比较低,人物参与者缺乏与观看者的正面接触,图片设计者多采用中、远镜头,虽客观呈现景物特点,但与观看者保持较为疏远的关系。建议网站丰富再现意义的类型,增加叙事再现的使用,增加参与者与观看者的正面接触;适当采取前景化、分割线等手段,借用近距离镜头将观看者代入到图片情境中。
