MAG-JAM: Jamming Detection via Magnetic Emissions

Wireless networks inherently rely on a shared medium, making them exposed to jamming attacks. In this paper, we present MAG-JAM, a novel solution for jamming detection in static and mobile scenarios leveraging the physical layer properties of wireless communication by analyzing the magnetic emissions near the antennas of target wireless devices. To the best of our knowledge, MAG-JAM represents the first solution based on the key observation that the magnetic emissions profile of normal wireless communication between transmitter-receiver pairs is different from the magnetic emissions profile when an active jamming signal starts affecting the communication channel. MAG-JAM has several advantages: its implementation requires mainly an inexpensive magnetic sensor, it is non-invasive and privacy-preserving as it is implemented as a standalone unit, does not need access to the wireless device, and demonstrates a remarkable performance. We design and implement a proof of concept jamming detection system using a cheap magnetic sensor and test MAG-JAM on a set of different wireless devices with a perfect score in jamming detection using no more than 1 s of the magnetic emissions collected by the magnetic sensor under a normalized jamming power of 0.1–1. In addition, we also implement a more advanced jamming detection system using a specialized magnetic probe and autoencoders that, using just 150 ms of collected data, achieves a minimum of 0.91 F1-Score in detecting jamming with a normalized power of 0.2 and an F1-Score of 1 for jamming powers greater than 0.4.