Ultrasound Tracking Could Be Used to Deanonymize Tor Users

Bleeping Computer, 1/3/2017

Cybersecurity researchers recently discovered that ultrasound cross-device tracking (uXDT), in which a web page plays an ultrasound signal that prompts nearby devices to identify themselves via ultrasound, could be effective even when users are using the anonymization proxy Tor. This provides an example of the continual arms race between privacy-enhancing technologies and privacy-invading technologies.