Reconfigurable intelligent surfaces reveal new method of attacking Wi-Fi networks

Wireless connections are common in most households today. From your lights to your heating, everything can be connected and controlled through Wi-Fi. However, wireless technology is inherently vulnerable to the threat of jamming.

Scientists at the Max Planck Institute for Security and Privacy (MPI-SP) and Ruhr University Bochum (RUB) show that reconfigurable intelligent surfaces (RIS) technology allows attackers to significantly improve jamming attacks by enabling fine-grained spatial control.

Criminals use wireless jamming attacks to disable smart home security systems or prevent cars from locking. The attacker transmits an interfering signal to overshadow the legitimate signal, with the user experiencing denial of service. However, criminals may rely on emerging technologies to develop new and increasingly sophisticated attack strategies.

Precision attacks bypass alarms

As an example, a complex automatic manufacturing process relies on wireless connectivity for its devices. If the attackers were to penetrate the network and sabotage it, an alarm would be automatically triggered. However, if the attacker were capable of selectively jamming just one device and leaving the others intact, the disruption would be less likely flagged.

Scientists at RUB and MPI-SP investigated how recent technological advancements in reconfigurable intelligent surfaces (RISs) lowers the bar to realize such selective jamming attacks. In particular, they showed that by using an RIS, the attack effect can be confined to one or multiple selected devices while other nearby devices remain unaffected. The paper is published on the arXiv preprint server.

RISs are software-controlled surfaces that have emerged from metamaterial research and can be used to intelligently control radio-wave propagation. With these unique capabilities, RIS technology holds great promise to complement future 6G wireless networks. The prototype device used in this study was developed by a team of scientists from TH Köln and Ruhr University Bochum.

Easier defense against attacks

The team of scientists from MPI-SP and RUB employed this technology to perform selective jamming. “You can think of the RIS device like a disco ball, which can reflect radio waves. The difference is that we can manipulate each mirror facet so that it directs the waves where we want them to,” says Philipp Mackensen, lead author of this study. The team of researchers used the RIS system to successfully target just one of two devices, which were placed in very close proximity.

Even if the devices were stacked one over the other, at a distance as small as 5mm, the selective attack of one device was successful. “The potential advancement of jamming capabilities using RIS technology was largely unexplored before this study,” notes Paul Staat, co-author of the paper.

“Achieving such a high spatial resolution of targeting with relatively inexpensive and low complexity tools would not be possible without the RIS technology”. Along with their results, the authors also discuss how to mitigate the threat of RIS-based wireless jamming attacks.

The paper will be presented at the 32nd Network & Distributed System Security (NDSS) Symposium, a security conference, in February in San Diego.