Biblio

Cyber-Physical Power Systems (CPPSs) currently face an increasing number of security attacks and lack methods for optimal proactive security decisions to defend the attacks. This paper proposed an optimal defensive method based on game theory to minimize the system performance deterioration of CPPSs under cyberspace attacks. The reinforcement learning algorithmic solution is used to obtain the Nash equilibrium and a set of metrics of system vulnerabilities are adopted to quantify the cost of defense against cyber-attacks. The minimax-Q algorithm is utilized to obtain the optimal defense strategy without the availability of the attacker's information. The proposed solution is assessed through experiments based on a realistic power generation microsystem testbed and the numerical results confirmed its effectiveness.

The traditional KNN algorithm takes insufficient consideration of the spatial distribution of training samples, which leads to low accuracy in processing high-dimensional data sets. Moreover, the generation of k nearest neighbors requires all known samples to participate in the distance calculation, resulting in high time overhead. To solve these problems, a feature subspace based KNN algorithm (Feature Subspace KNN, FSS-KNN) is proposed in this paper. First, the FSS-KNN algorithm solves all the feature subspaces according to the distribution of the training samples in the feature space, so as to ensure that the samples in the same subspace have higher similarity. Second, the corresponding feature subspace is matched for the test set samples. On this basis, the search of k nearest neighbors is carried out in the corresponding subspace first, thus improving the accuracy and efficiency of the algorithm. Experimental results show that compared with the traditional KNN algorithm, FSS-KNN algorithm improves the accuracy and efficiency on Kaggle data set and UCI data set. Compared with the other four classical machine learning algorithms, FSS-KNN algorithm can significantly improve the accuracy.

With the continuous development of the Internet of Vehicles, vehicles are no longer isolated nodes, but become a node in the car network. The open Internet will introduce traditional security issues into the Internet of Things. In order to ensure the safety of the networked cars, we hope to set up an intrusion detection system (IDS) on the vehicle terminal to detect and intercept network attacks. In our work, we designed an intrusion detection system for the Internet of Vehicles based on a convolutional neural network, which can run in a low-powered embedded vehicle terminal to monitor the data in the car network in real time. Moreover, for the case of packet encryption in some car networks, we have also designed a separate version for intrusion detection by analyzing the packet header. Experiments have shown that our system can guarantee high accuracy detection at low latency for attack traffic.