Privacy preserving scheme for location and content protection in location-based services

Location-Based Services (LBSs) have been facilitating and enriching people’s daily lives. While users enjoy plenty of conveniences, privacy disclosure in terms of both location information and query contents is common. Most of the existing solutions mainly focus on location privacy and adopt K-anonymity principle to preserve user’s privacy. However, these methods are vulnerable to protect user’s query content. In this paper, we propose a Privacy Preserving and Content Protection (PPCP) scheme for LBSs users. Unlike most of researches requiring a trusted third party (TTP), our scheme is based on a semi-trusted middle entity, which is unaware of both the exact location information about issuer and query content in the user’s requirement. We utilize space filling curve to transform user location and protect user query content based on encryption technology, so that the proposed scheme can provide enhanced location privacy and query privacy protection in both snapshot and continuous LBSs.