UC San Diego Researchers Develop Breakthrough Firmware Update to Hide Bluetooth Fingerprints, Enhancing Device Privacy

Researchers at UC San Diego have pioneered a firmware update that effectively hides a device’s Bluetooth fingerprint, eliminating a significant tracking vulnerability and paving the way for enhanced privacy in mobile technology.

A groundbreaking development by a team of researchers from the University of California, San Diego, promises to significantly enhance user privacy by addressing a vulnerability in mobile device Bluetooth signals. This vulnerability, which allowed for tracking devices via their unique Bluetooth fingerprints, has been effectively mitigated by a simple firmware update.

The Discovery and Solution

The vulnerability was first identified by the same UC San Diego research team, led by faculty members Aaron Schulman and Dinesh Bharadia. Their initial findings, presented at the 2022 IEEE Security & Privacy conference, revealed that every mobile device emits Bluetooth signals with unique distortions, or fingerprints, due to small hardware imperfections. These fingerprints, an unintended byproduct of the manufacturing process, made it possible to track individual devices.

To counter this, the researchers developed a method involving multiple layers of randomization. This technique can be likened to using several layers of contact lenses to continuously change a person’s eye color, making it nearly impossible to determine the original color. The solution was presented at the 2024 IEEE Security & Privacy conference, demonstrating that even the most sophisticated attackers, such as nation-state entities, would be unable to track devices with the new firmware update.

Implementation and Testing

The UC San Diego team implemented a prototype of this new defense on the Texas Instruments CC2640 chipset, which is commonly used in smart devices like fitness trackers and lighting systems. The results were impressive. Their tests showed that an adversary would need to continuously observe a device for over ten days to achieve the same level of tracking accuracy that could previously be achieved within a minute.

“This means that the fingerprints are no longer useful for the attacker to infer the identity of the device, and the optimal attacker can barely do better than a random guess,” Bharadia said in a news release. “You can’t track the phone’s fingerprint even if you’re sitting right next to it, because both MAC and PHY identities keep changing.”

Future Prospects

The researchers are now seeking industry partners to integrate this technology into widely-used Bluetooth chipsets.

“This defense can be rolled out incrementally, requiring only software modification on at least one widely-used Bluetooth Low Energy chipset. But in order to deploy this defense widely, we need to partner with Bluetooth chip manufacturers,” Hadi Givehchian, the paper’s first author and a doctoral student at UC San Diego’s Department of Computer Science and Engineering, said in the news release.

Additionally, the team believes that their method could also be adapted to obfuscate WiFi fingerprints, further extending the privacy benefits.


This development is a significant step forward in protecting user privacy in an increasingly connected world. By addressing the vulnerabilities inherent in Bluetooth and potentially WiFi fingerprints, the UC San Diego team is paving the way for more secure and private mobile device usage.

The UC San Diego team comprised of researchers from both the Department of Computer Science and Engineering and the Department of Electrical and Computer Engineering.