It would seem that we each interfere with WiFi signals in a unique way, which can be measured thanks to several researchers who have created a system they call WhoFi. Their research builds on what the IEEE calls Wi-Fi Sensing, which encapsulates a variety of uses for WiFi other than data transfer. If you haven’t run into the term before, it turns out you can use the specific interference patterns created in a WiFi signal to do things such as seeing through walls, detecting falls and even recognizing sign language. There are certainly better ways to do each of these tasks, but with the right setup you can use WiFi to do this and more.
WhoFi is a new way to take advantage of the interference humans cause in WiFi signals to identify specific people, as it turns out we each have a unique interference pattern, or fingerprint if you will. It’s not that WhoFi can figure out your identity, rather it can track you as you move around, since every time you interfere with a WiFi signal you do so in exactly the same way. This is a little scary, as you could use WhoFi to track people as they move around a building, without needing line of site as WiFi can ‘see’ through walls. It would be more challenging to track someone if they travel beyond the range of a WhoFi detector, but as your pattern is unique you would be immediately identified the next time you were within range of another WhoFi enabled network.
Maybe we could also determine if people who always seem to have WiFi problems are actually creating stronger interference patterns than most and are indeed the main cause of their own problems.