Authors: Quoc Cuong To; Tran Khanh Dang; Josef Küng
Addresses: Faculty of Computer Science and Engineering, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet street, District 10, Ho Chi Minh City, Vietnam ' Faculty of Computer Science and Engineering, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet street, District 10, Ho Chi Minh City, Vietnam ' Institute of Application Oriented Knowledge Processing, Johannes Kepler University Linz, Altenberger Straße 69, A-4040 Linz, Austria
Abstract: Preserving user's privacy has recently drawn special attention in the field of location-based services and many techniques such as k-anonymity or obfuscation have been suggested to protect user's privacy. All of these traditional techniques are, however, geometry-based and separated from the database level. This separation causes the query processing to involve in two phases, querying the database to retrieve the exact locations of users and then modifying them to decrease the quality of this information. This two-phase process is time-consuming due to the number of disk accesses required to retrieve the user's exact location. Also, these geometry-based techniques cannot guarantee location privacy when the adversary gains knowledge about the geography of the obfuscated region. We address these problems by proposing Hilbert-based framework for preserving user's privacy and Bob-tree for supporting geographic-aware obfuscation. Experiments and analyses show that this framework provides a significant improvement over the algorithm separated from the database level for both query processing time and location privacy protection.
Keywords: location-based services; LBS; privacy preservation; privacy protection; spatio-temporal indexing; geographic-aware obfuscation; B+-tree; Hilbert curve; security.
International Journal of Intelligent Information and Database Systems, 2013 Vol.7 No.2, pp.113 - 134
Received: 17 Dec 2011
Accepted: 20 Apr 2012
Published online: 26 Apr 2013 *