DOLOS: Tricking the Wi-Fi APs with Incorrect User Locations

TL;DR

DOLOS is a software-only system that obfuscates Wi-Fi signals to protect user location privacy by disrupting the assumptions of existing localization systems, significantly reducing their accuracy without affecting communication quality.

Contribution

It introduces a novel signal obfuscation method that can be implemented on existing Wi-Fi devices to enhance location privacy without additional hardware.

Findings

Degrades localization accuracy by 6x for single AP scenarios

Reduces accuracy by 2.5x in multi-AP scenarios

Maintains Wi-Fi communication performance

Abstract

Wi-Fi-based indoor localization has been extensively studied for context-aware services. As a result, the accurate Wi-Fi-based indoor localization introduces a great location privacy threat. However, the existing solutions for location privacy protection are hard to implement on current devices. They require extra hardware deployment in the environment or hardware modifications at the transmitter or receiver side. To this end, we propose DOLOS, a system that can protect the location privacy of the Wi-Fi user with a novel signal obfuscation approach. DOLOSis a software-only solution that can be deployed on existing protocol-compliant Wi-Fi user devices. We provide this obfuscation by invalidating a simple assumption made by most localization systems -- "direct path signal arrives earlier than all the reflections to distinguish this direct path prior to estimating the location". However, DOLOS creates a novel software fix that allows the user to transmit the signal wherein this direct path arrives later, creating ambiguity in the location estimates. Our experimental results demonstrate DOLOS can degrade the localization accuracy of state-of-art systems by 6x for a single AP and 2.5x for multiple AP scenarios, thereby protecting the Wi-Fi user's location privacy without compromising the Wi-Fi communication performance.