On Guard Against Wireless Jamming

Estimated reading time: 2 minutes

As the field of wireless communication advances, the sheer number and variety of smart devices and physical objects connected to the internet will only increase. In this internet of things (IoT) universe, we might observe medical sensors monitoring vital signs in patients in real time, and self-driving cars updating their location every millisecond to avoid collisions.

If society is to rely on these IoT systems for critical functions, protecting them from cyberattacks will be vital. A team of researchers at A*STAR’s Institute for Infocomm Research (I²R) has thus developed a strategy involving a ‘guarding node’ to keep IoT networks secure.

In a typical IoT setup, several remote devices transmit information wirelessly to a base station, which must then separate the signal it receives into individual components, then decipher the original information sent by each device. “The base station has to do this ‘blind,’ without any prior knowledge about the true input signals it is meant to receive,” explained Peng Zhang, a Research Scientist at I²R who led the study.

However, this leaves the network open to being jammed by an attacker transmitting a false signal using the same channel as one of the remote devices, which would contaminate the information received by the base station. This is where the guarding node comes into play.

Put simply, the guarding node can be preconfigured at the base station to inject a known guarding signal into other incoming signals from remote devices—think of this as a barcode being overlaid onto the received signal. When the base station recovers the individual incoming signals from the received signal, it should be able to derive the barcode correctly in a jamming-free environment.

Incoming signals that have been subjected to jamming will have the barcode tampered with in a specific manner. Importantly, by analyzing the pattern of tampering, the base station can derive the original signals using an algorithm. This guard node approach enables greater security over low latency connections, the researchers said.

The traditional response to a jamming attack also introduces communication delays as it requires two separate steps: jamming detection, followed by jamming countermeasures such as switching the communication frequency between the base station and the remote device.

“In contrast, the guard node approach enables us to simultaneously detect the jamming attack, reject the jamming signals, and recover the legitimate signals, with just one snapshot of the received signal, preserving a network’s communication speed and security,” Zhang noted.

Moving forward, Zhang’s team will work on simulating modulated signals that are typical of an industrial IoT environment and demonstrate performance enhancements linked to their guard node approach.