Abstract
The widespread adoption of location-based services (LBS) raises increasing concerns for the protection of personal location information. A common strategy, referred to as obfuscation, to protect location privacy is based on forwarding
the LSB provider a coarse user location instead of the actual
user location. Conventional approaches, based on such tech-
nique, are however based only on geometric methods and
therefore are unable to assure privacy when the adversary
has semantic knowledge about the reference spatial context.
This paper provides a comprehensive solution to this problem. Our solution presents a novel approach that obfuscates
the user location by taking into account the semantic knowl-
edge about the reference space. In the paper, we dene sev-
eral theoretical notions underlying our approach. We then
propose two dierent strategies for generating obfuscated
spaces. The paper also includes several experimental results
assessing performance, storage requirements and accuracy
for the two approaches. The paper also discusses the system
architecture and shows that the approach can be deployed also for clients running on small devices.
