基于收缩自编码器的无人机GPS欺骗攻击协同检测方法
Collaborative Detection Method of UAV GPS Spoofing Attack Based on Shrink Autoencoder
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摘要: GPS欺骗攻击是一种通过改变GPS信号来诱导接收机导航系统的恶意攻击,它会使无人机产生偏离运行轨迹、飞入禁飞区、强制降落等异常行为。当前对GPS欺骗攻击的检测仍存在模型训练效率较低、检测性能不高等问题,基于此,本文提出了一种无人机GPS欺骗攻击协同检测方法。该方法采用联邦学习框架,多个基站通过本地接收的无人机运行数据协同训练异常检测模型并计算异常检测阈值,进而检测无人机是否存在GPS欺骗攻击。此外,为了防止在联邦学习过程中不同基站本地训练数据分布差异过大导致模型训练效果降低的问题,本文采用收缩自编码器作为异常检测模型。与自编码器相比,收缩自编码器通过在损失函数中加入新的损失项,将训练数据样本的低维表示压缩到更小的范围内,从而使模型在训练过程中能够更好地学习训练数据样本的低维特征,提高了模型区分正常数据和异常数据的能力。基于公开数据集的实验结果表明,本文提出的方法对无人机GPS欺骗攻击的准确率、查准率和召回率分别达到了96.49%、96.03%和93.85%,比原始的自编码器提高了1.63%、0.8%和4.62%,且与采用集中式学习框架相比,本文提出的协同检测方法能够显著提高模型的训练效率。同时,本文提出的联邦学习收缩自编码器受平衡系数改变的影响最小,在异常检测阈值计算不准确的情况下仍然能够达到较好的检测结果。Abstract: As a malicious attack by manipulating the received GPS signal of an unmanned aerial vehicle (UAV), a GPS spoofing attack may cause severe abnormal behaviors in UAVs, such as deviating from the intended path, flying into the no-fly zone, and forced landing. Therefore, to ensure the safety of UAVs, it is urgently demanded to investigate the GPS spoofing attack detection methods. Currently, the detection of GPS spoofing attacks still suffers from low model training efficiency and low detection performance. To tackle this problem, a collaborative UAV GPS spoofing attack detection scheme is proposed in this paper. Specifically, a federated learning framework is adopted, where multiple base stations (BSs) train the anomaly detection model and calculate the anomaly detection threshold with locally received UAV operation data, to detect whether the UAV suffers a GPS spoofing attack. To mitigate the performance deterioration resulting from uneven data distribution in the federated learning model, the shrink autoencoder is used. Compared with conventional autoencoders, a new loss term is added to the loss function in the shrink autoencoder, which can compress the low-dimensional representation of the training data sample into a smaller range. Thus, the low-dimensional features of the training data can be captured more easily, and the distinguishing capability of abnormal data can be improved. Experimental results with an open data set show that the accuracy rate, precision rate, and recall rate with the proposed scheme can reach up to 96.49%, 96.03%, and 93.85%, respectively, which are 1.63%, 0.8%, and 4.62% higher, respectively, than the original autoencoder. It has been proven that the shrink autoencoder can improve the detection performance of the collaborative detection method. Compared with the centralized learning framework, the proposed collaborative detection method can improve training efficiency. Moreover, the proposed shrink autoencoder, within a federated learning framework, shows the least sensitivity to changes in the balance coefficient, maintaining good detection results even with an inaccurate anomaly detection threshold. In conclusion, simulation experiments prove that the collaborative UAV GPS spoofing attack detection scheme proposed in this paper can achieve better detection performance and higher model training efficiency on open data sets.