  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.
