Achieving Efficient Query Privacy for Location Based Services

  • Femi Olumofin
  • Piotr K. Tysowski
  • Ian Goldberg
  • Urs Hengartner
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6205)


Mobile smartphone users frequently need to search for nearby points of interest from a location based service, but in a way that preserves the privacy of the users’ locations. We present a technique for private information retrieval that allows a user to retrieve information from a database server without revealing what is actually being retrieved from the server. We perform the retrieval operation in a computationally efficient manner to make it practical for resource-constrained hardware such as smartphones, which have limited processing power, memory, and wireless bandwidth. In particular, our algorithm makes use of a variable-sized cloaking region that increases the location privacy of the user at the cost of additional computation, but maintains the same traffic cost. Our proposal does not require the use of a trusted third-party component, and ensures that we find a good compromise between user privacy and computational efficiency. We evaluated our approach with a proof-of-concept implementation over a commercial-grade database of points of interest. We also measured the performance of our query technique on a smartphone and wireless network.


Location based service private information retrieval various-size grid Hilbert curve 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Femi Olumofin
    • 1
  • Piotr K. Tysowski
    • 2
  • Ian Goldberg
    • 1
  • Urs Hengartner
    • 1
  1. 1.Cheriton School of Computer ScienceUniversity of WaterlooWaterlooCanada
  2. 2.Department of Electrical and Computer EngineeringUniversity of WaterlooWaterlooCanada

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