基于深度特征学习的网络流量异常检测方法

针对网络流量异常检测过程中提取的流量特征准确性低、鲁棒性差导致流量攻击检测率低、误报率高等问题，该文结合堆叠降噪自编码器(SDA)和softmax，提出一种基于深度特征学习的网络流量异常检测方法。首先基于粒子群优化算法设计SDA结构两阶段寻优算法:根据流量检测准确率依次对隐藏层层数及每层节点数进行寻优，确定搜索空间中的最优SDA结构，从而提高SDA提取特征的准确性。然后采用小批量梯度下降算法对优化的SDA进行训练，通过最小化含噪数据重构向量与原始输入向量间的差异，提取具有较强鲁棒性的流量特征。最后基于提取的流量特征对softmax进行训练构建异常检测分类器，从而实现对流量攻击的高性能检测。实验结果表明:该文所提方法可根据实验数据及其分类任务动态调整SDA结构，提取的流量特征具有更高的准确性和鲁棒性，流量攻击检测率高、误报率低。

Network Traffic Anomaly Detection Method Based on Deep Features Learning

In view of the problems of low attack detection rate and high false positive rate caused by poor accuracy and robustness of the extracted traffic features in network traffic anomaly detection, a network traffic anomaly detection method based on deep features learning is proposed, which is combined with Stacked Denoising Autoencoders (SDA) and softmax. Firstly, a two-stage optimization algorithm is designed based on particle swarm optimization algorithm to optimize the structure of SDA, the number of hidden layers and nodes in each layer is optimized successively based on the traffic detection accuracy, and the optimal structure of SDA in the search space is determined, improving the accuracy of traffic features extracted by SDA. Secondly, the optimized SDA is trained by the mini-batch gradient descent algorithm, and the traffic features with strong robustness are extracted by minimizing the difference between the reconstruction vector of the corrupted data and the original input vector. Finally, softmax is trained by the extracted traffic features to construct an anomaly detection classifier for detecting traffic attacks with high performance. The experimental results show that the proposed method can adjust the structure of SDA based on the experimental data and its classification tasks, extract traffic features with a higher accuracy and robustness, and detect traffic attacks with high detection rate and low false positive rate.