Date Added: Jan 2011
The emerging participatory sensing applications have brought a privacy risk where users expose their location information. Most of the existing solutions preserve location privacy by generalizing a precise user location to a coarse-grained location, and hence they cannot be applied in those applications requiring fine-grained location information. To address this issue, in this paper the authors propose a novel method to preserve location privacy by anonymizing coarse-grained locations and retaining fine-grained locations using Attribute Based Encryption (ABE). In addition, they do not assume the service provider is an trustworthy entity, making their solution more feasible to practical applications. They present and analyze their security model, and evaluate the performance and scalability of their system.