Matt Edmondson is a digital forensics expert and federal agent with the Department of Homeland Security, and he created a Raspberry Pi-based anti-tracking tool after a friend got worried they were being followed. No, he won’t say who the friend is. Matt is terrible at sharing gossip, which makes him a very good federal agent.
What is it made of?
The entire device fits inside a waterproof case the size of a shoebox. A Raspberry Pi 3 runs the software while a Wi-Fi card and wireless signal detectors look for nearby devices. A portable charger powers everything, and a touchscreen shares each alert the device sends so the user gets a visual indication of which devices keep popping up and how often.
How does it work?
The device runs Kismet software to detect smartphones and tablets nearby that are looking for Wi-Fi or trying to connect to Bluetooth devices. Kismet is a network detector, packet sniffer, and intrusion detection system, and it runs with any wireless card that supports raw monitoring mode.
We all know our phones track our app usage and location, but you may not be aware that your phone is also constantly looking for wireless networks around it. And it gets especially excited when it finds a network it has connected to before. “Especially excited” is the technical term for “doing something different which notifies Kismet in a special and different way”. If Kismet finds a device that it has seen in the last twenty minutes, it flashes up a warning to let the user know they might be being tracked.
Matt wrote code in Python to keep lists of the devices that his anti-tracking tool has come into contact with, so that the software can check its log and see the last time it came across each device.
This homemade tracking device is designed for use on the move. If you’re sitting for a long time in one place where lots of other people are also hanging around for longer periods, like a cinema or a restaurant, you’ll get pinged every twenty minutes to let you know your seat neighbours might be tracking you.