Anonymous User Tracking for Location-Based Community Services

  • Peter Ruppel
  • Georg Treu
  • Axel Küpper
  • Claudia Linnhoff-Popien
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3987)


In location-based community services (LBCSs), the positions of several targets are interrelated. Users can be notified when targets approach or separate from each other. Typical application areas are instant messaging, mobile gaming, dating, fleet management and logistics, as well as child tracking. Finding appropriate anonymization techniques for LBCSs is a hard problem since (i) the targets are continuously monitored and (ii) identifiers of the targets must not change in order to maintain coherence within a community. LBCSs are inherently stateful. Therefore, existing anonymization techniques for location-based services are not suited for LBCSs. In this paper, we present an anonymization technique for LBCSs, which employs distance-preserving coordinate transformations in conjunction with pseudonyms. It is based on the idea that for determining the distance between targets only relative positions are needed. It supports target anonymity, either with respect to the location provider, which collects the position fixes, or the LBS provider. The paper also presents the results of simulations, which we have performed in order to evaluate the proposed mechanism.


Pervasive Computing Location Privacy Location Provider Anonymous User Proximity Distance 


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  1. [AEM+04]
    Amir, A., Efrat, A., Myllymaki, J., Palaniappan, L., Wampler, K.: Buddy tracking - efficient proximity detection among mobile friends. In: INFOCOM (2004)Google Scholar
  2. [BMH92]
    Badel, A., Mornon, J.P., Hazout, S.: Searching for geometric molecular shape complementarity using bidimensional surface profiles. Journal of Molecular Graphics 10(4), 205–211 (1992)CrossRefGoogle Scholar
  3. [BPB+04]
    Bakken, D.E., Parameswaran, R., Blough, D.M., Franz, A.A., Palmer, T.J.: Data obfuscation: anonymity and desensitization of usable data sets. IEEE Security & Privacy, 34–41 (November/December 2004)Google Scholar
  4. [BS03]
    Beresford, A.R., Stajano, F.: Location privacy in pervasive computing. IEEE Pervasive Computing 2(1), 46–55 (2003)CrossRefGoogle Scholar
  5. [Cha81]
    Chaum, D.L.: Untraceable electronic mail, return addresses, and digital pseudonyms. Communications of the ACM 24(2), 84–90 (1981)CrossRefGoogle Scholar
  6. [DK05]
    Duckham, M., Kulik, L.: A formal model of obfuscation and negotiation for location privacy. In: Gellersen, H.-W., Want, R., Schmidt, A. (eds.) PERVASIVE 2005. LNCS, vol. 3468, pp. 152–170. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  7. [FJ04]
    Frikken, K.B., AAtallah, M.J.: Privacy preserving route planning. In: WPES 2004: Proceedings of the 2004 ACM workshop on Privacy in the electronic society, pp. 8–15. ACM Press, New York (2004)Google Scholar
  8. [GBG04]
    Gruteser, M., Bredin, J., Grunwald, D.: Path privacy in location-aware computing. In: Proceedings of MobiSys 2004 Workshop on Context Awareness (June 2004)Google Scholar
  9. [GG03]
    Gruteser, M., Grunwald, D.: Anonymous Usage of Location-Based Services Through Spatial and Temporal Cloaking. In: Proceedings of the First International Conference on Mobile Systems, Applications, and Services (May 2003)Google Scholar
  10. [GHT04]
    Görlach, A., Heinemann, A., Terpstra, W.W.: Survey on location privacy in pervasive computing. In: Robinson, P., Vogt, H., Wagealla, W. (eds.) Privacy, Security and Trust within the Context of Pervasive Computing (Workshop at Pervasive 2004), Vienna, Austria, April 2004. The Kluwer International Series in Engineering and Computer Science, vol. 780, Springer, Heidelberg (2004)Google Scholar
  11. [KT05]
    Küpper, A., Treu, G.: From location to position management: User tracking for location-based services. In: Müller, P., Gotzhein, R., Schmitt, J.B. (eds.) Tagungsband der ITG/GI-Fachtagung Kommunikation in Verteilten Systemen (KiVS 2005), Gesellschaft für Informatik (GI), Kaiserslautern, Germany, February 2005. Lecture Notes in Informatics (LNI), vol. 61, pp. 81–88 (2005)Google Scholar
  12. [Küp05]
    Küpper, A.: Location–based Services — Fundamentals and Operation, August 2005. John Wiley & Sons, Chichester (2005)CrossRefGoogle Scholar
  13. [LR02]
    Leonhardi, A., Rothermel, K.: Protocols for updating highly accurate location information. In: Behcet, A. (ed.) Geographic Location in the Internet, pp. 111–141. Kluwer Academic Publishers, Dordrecht (2002)CrossRefGoogle Scholar
  14. [MdB02]
    Meratnia, N., de By, R.A.: Aggregation and comparison of trajectories. In: GIS 2002: Proceedings of the 10th ACM international symposium on Advances in geographic information systems, pp. 49–54. ACM Press, New York (2002)Google Scholar
  15. [MFD03]
    Myles, G., Friday, A., Davies, N.: Preserving privacy in environments with location-based applications. IEEE Pervasive Computing 2(1), 56–64 (2003)CrossRefGoogle Scholar
  16. [MG95]
    Mehrotra, R., Gary, J.E.: Similar-shape retrieval in shape data management. IEEE Computer 28(2), 57–62 (1995)CrossRefGoogle Scholar
  17. [PK01]
    Pfitzmann, A., Köhntopp, M.: Anonymity, Unobservability, and Pseudonymity - A Proposal for Terminology. In: Federrath, H. (ed.) Designing Privacy Enhancing Technologies. LNCS, vol. 2009, pp. 1–9. Springer, Heidelberg (2001)CrossRefGoogle Scholar
  18. [Swe02]
    Sweeney, L.: k-anonymity: a model for protecting privacy. International Journal on Uncertainty, Fuzziness and Knowledge-based Systems 10(5), 557–570 (2002)MathSciNetCrossRefMATHGoogle Scholar
  19. [TK05]
    Treu, G., Küpper, A.: Efficient Proximity Detection for Location Based Services. In: Proceedings of the Joint 2nd Workshop on Positioning, Navigation and Communication 2005 (WPNC 2005) and 1st Ultra–Wideband Expert Talk (UET 2005), Hannover, Germany (March 2005)Google Scholar
  20. [TKR05]
    Treu, G., Küpper, A., Ruppel, P.: Anonymization in proactive location based community services. In: Advances in Pervasive Computing. Adjunct Proceedings of the 3rd International Conference on Pervasive Computing, Munich, Germany, Mai 2005, vol. 191, ”Osterreichische Computer Gesellschaft (2005)Google Scholar
  21. [YAS03]
    Yanagisawa, Y., Akahani, J., Satoh, T.: Shape-based similarity query for trajectory of mobile objects. In: Chen, M.-S., Chrysanthis, P.K., Sloman, M., Zaslavsky, A. (eds.) MDM 2003. LNCS, vol. 2574, pp. 63–77. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  22. [ZRM05]
    Zou, X., Ramamurthy, B., Magliveras, S.S.: Secure Group Communications over Data Networks. Springer Science+Business Media, Inc., Heidelberg (2005)MATHGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Peter Ruppel
    • 1
  • Georg Treu
    • 1
  • Axel Küpper
    • 1
  • Claudia Linnhoff-Popien
    • 1
  1. 1.Mobile and Distributed Systems Group, Institute for InformaticsLudwig-Maximilian University MunichGermany

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