Optimizing Mixing in Pervasive Networks: A Graph-Theoretic Perspective

  • Murtuza Jadliwala
  • Igor Bilogrevic
  • Jean-Pierre Hubaux
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6879)


One major concern in pervasive wireless applications is location privacy, where malicious eavesdroppers, based on static device identifiers, can continuously track users. As a commonly adopted countermeasure to prevent such identifier-based tracking, devices regularly and simultaneously change their identifiers in special areas called mix-zones. Although mix-zones provide spatio-temporal de-correlations between old and new identifiers, pseudonym changes, depending on the position of the mix-zone, can incur a substantial cost on the network due to lost communications and additional resources such as energy. In this paper, we address this trade-off by studying the problem of determining an optimal set of mix-zones such that the degree of mixing in the network is maximized, whereas the overall network-wide mixing cost is minimized. We follow a graph-theoretic approach and model the optimal mixing problem as a novel generalization of the vertex cover problem, called the Mix Cover (MC) problem. We propose three bounded-ratio approximation algorithms for the MC problem and validate them by an empirical evaluation of their performance on real data. The combinatorics-based approach followed here enables us to study the feasibility of determining optimal mix-zones regularly and under dynamic network conditions.


Road Network Vertex Cover Linear Program Relaxation Location Privacy Vehicular Network 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Murtuza Jadliwala
    • 1
  • Igor Bilogrevic
    • 1
  • Jean-Pierre Hubaux
    • 1
  1. 1.LCA1, EPFLLausanneSwitzerland

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