"Bluetooth Signals Can Be Used to Identify and Track Smartphones"

A team of engineers at the University of California San Diego presented findings at the IEEE Security & Privacy conference in San Francisco, California, from their demonstration that it is feasible to track individuals using Bluetooth. This is the first time researchers showed that the Bluetooth signals constantly emitted by mobile phones have a unique fingerprint, which can be used to track an individual's movements. Mobile devices, such as phones, smartwatches, and fitness trackers, send out signals called Bluetooth beacons at a rate of about 500 beacons per minute. These beacons make features like Apple's lost device monitoring service, COVID-19 tracing apps, and more possible. Wireless fingerprinting has been discovered in Wi-Fi and other wireless technologies, according to previous studies. The UC San Diego researchers discovered that this type of tracking could also be done with Bluetooth and with high accuracy. Every wireless device has small manufacturing flaws in its hardware that is unique to it. The fingerprints come from these manufacturing imperfections. Flaws in Bluetooth devices cause distinct distortions that can be used as a fingerprint to identify and track a specific device. In the case of Bluetooth, this would allow an attacker to evade anti-tracking measures such as continuously changing the address a mobile device uses to connect to Internet networks. Previous Wi-Fi fingerprinting techniques rely on the fact that Wi-Fi signals contain a long known sequence known as the preamble. Preambles for Bluetooth beacon signals, on the other hand, are significantly short, thus resulting in inaccurate fingerprints and the ineffectiveness of prior techniques for Bluetooth tracking. Therefore, the researchers designed a new method that does not rely on the preamble but looks at the entire Bluetooth signal. Their algorithm estimates two different values discovered in Bluetooth signals, which vary based on the Bluetooth hardware's defects, giving the device's unique fingerprint. This article continues to discuss the demonstration of the team's Bluetooth tracking method. 

UC San Diego News Center reports "Bluetooth Signals Can Be Used to Identify and Track Smartphones"