New Technology Can Detect Physical Attacks Using WiFi Signals

This post is also available in: עברית (Hebrew)

The Internet of Things (IoT) is fast becoming an everyday reality, with about half of enterprises set to deploy IoT solutions by the end of 2016. The emerging field offers many advantages, but harbours many risks as well. Most research is conducted into improving the digital security of such devices, to prevent, and protect from, hacking attempts.

Strong encryption can, and should, be implemented on all levels of IoT devices. Safer design practices must be incorporated at the early stages of development, before these systems get too large and unwieldy to secure properly. All this is true, but an often overlooked aspect of IoT security is the physical layer.

Researchers from Lancaster University’s School of Computing and Communications in the United Kingdom are tackling precisely this problem. They have devised a method of analysing WiFi signals to detect tampering with the devices. The method uses multiple receivers to detect interference with devices that detect changes in the pattern of the wireless signal, known as Channel State Information (CSI).

A security camera, for instance, can have its communication link encrypted and secure, but all an attacker needs to bypass it is to simply turn it away from its designated area of focus. Software-based security would be unable to detect this disruption, but the camera would be rendered essentially useless.

The method outlined in the ‘Using Channel State Information for Tamper Detection in the Internet of Things’ study would provide a vital defence against such an attack. Moreover, the algorithm developed by the team is able to distinguish between direct tampering attempts and natural environmental interference, such as a person walking through the WiFi signal.

“A large number of Internet of Things systems are using WiFi and many of these require a high level of security. This technique gives us a new way to introduce an additional layer of defence into our communication systems. Given that we use these systems around critically important infrastructure this additional protection is vital,” said Dr Utz Roedig, one of the report’s authors.