Network Anomaly Detection Based on Probabilistic Analysis

In this paper, we provide a detection technology for a common type of network intrusion (traffic flood attack) using an anomaly data detection method based on probabilistic model analysis. Victim’s computers under attack show various symptoms such as degradation of TCP throughput, increase of CPU usage, increase of RTT (Round Trip Time), frequent disconnection to the web sites, and etc. These symptoms can be used as components to comprise k-dimensional feature space of multivariate normal distribution where an anomaly detection method can be applied for the detection of the attack. These features are in general correlated one another. In other words, most of these symptoms are caused by the attack, so they are highly correlated. Thus we choose only a few of these features for the anomaly detection in multivariate normal distribution. We study this technology for those IoT networks prepared to provide u-health services in the future, where stable and consistent network connectivity is extremely important because the connectivity is highly related to the loss of human lives eventually.