Recently, several techniques have been proposed to protect
the user location privacy for location-based services in the Euclidean space
. Applying these techniques directly to the road network environment would lead to priva
cy leakage and inefficient query processing. In this paper, we propose a new location an
onymization algorithm that is designed specifically for the road network environme
nt. Our algorithm relies on the commonly used concept of spatial cloaking, where a use
r location is cloaked into a set of connected road segments of a minimum total length L including at least K users. Our algorithm is “query-aware” as it takes into accou
nt the query execution cost at a database server and the query quality, i.e., the number of objects returned to users by the database server, during the location anonymization process. In particular,we develop a new cost function that balances between the query execution cost and the query quality. Then, we introduce two versions of our algorithm, namely,puregreedy and randomized greedy, that aim to minimize the developed cost function and satisfy the user specified privacy requirements. To accommo
date intervals with a high workload, we introduce a shared execution paradigm that boosts the scalability of our location anonymization algorithm and the database server t
o support large numbers of queries received in a short time period. Extensive experimental results show that