To benefit from a location-based service, a person must reveal her location to the service. However, knowing the person's location might allow the service to re-identify the person. Location privacy based on k-anonymity addresses this threat by cloaking the person's location such that there are at least k − 1 other people within the cloaked area. We propose a distributed approach that integrates nicely with existing infrastructures for location-based services, as opposed to previous work. Our approach is based on homomorphic encryption and has several organizations, such as operators of cellphone networks, collaborate to let a user learn whether k-anonymity holds for her area without the organizations learning any additional information. We also outline several challenges that remain to be addressed.
In order to achieve location privacy based on the notion of k-anonymity, Zhong and Hengartner REF develop a protocol based on homomorphic encryption which can cloak a user's location in a way that there are at least k−1 other people within the cloaked area.
Toward a distributed k-anonymity protocol for location privacy
WPES '08
Computer Science