Abstract: Recently, the privacy preserving locationbased services has been a hot topic in data privacy preserving research fields. The existed researches on location privacy preserving mainly focused on Euclidean space. However, many locationbased services were under roadnetwork environment, whose distribution of users was possibly unbalanced, which could make the traditional location privacy models and methods under Euclidean space unusable. A location privacy protection algorithm was proposed to prevent the inferring attack caused by the unbalanced distribution of users in roadnetwork. The key idea of the proposed algorithm was that the cloaked segment set was constructed by sorting edges with edge weight and taking the geographical position distribution of users into consideration. Experimental analysis was designed by comparing the proposed algorithm and the traditional algorithm on the feasibility and effectiveness. Experimental results showed that the proposed algorithm was effective and feasible.

Key words: location privacy preserving, road network, unbalanced edge weight, edge weight inference attack, cloaking edge set, query cost