Efficient Delay-Based Internet-Wide Scanning Method for IoT Devices in Wireless LAN

Recently, Internet-wide scanning has emerged as an important element of detecting the security vulnerabilities of the Internet of Things (IoT) devices. However, Internet-wide scanning induces network congestion when sending a huge number of port scanning packets in a short time. The wireless networks are particularly subject to congestion from scanning traffic. Therefore, the scan rate should be low to reduce network congestion. However, as the number of IoT devices connected to a WLAN increases, a higher scan rate is required due to the excessive time consumption of low rate scanning. In this article, we propose a method for setting an optimal scan rate which is as high as possible without imposing congestion on a WLAN. To address this problem, we construct a model for quantifying the impact of scanning traffic on IoT data communication in a target network and demonstrate how scanning packet delay elicits the congestion of the target network. The validity of our model is evaluated and is corroborated by numerical analysis. In addition, numerical analysis results demonstrate the effectiveness of the proposed scan rate optimizing method in terms of low network congestion and a high scanning rate.