• 2nd IEEE international workshop on Privacy Aspects of Data Mining (PADM 2010) 

      Gkoulalas-Divanis, A.; Liu, K.; Verykios, V. S.; Wolff, R. (2010)
    • Concealing the position of individuals in location-based services 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2011)
      The offering of location based services requires an in- depth knowledge of the subscriber's whereabouts. Thus, without the existence of strict safeguards, the deployment of such services may easily breach user privacy. To ...
    • EXACT KNOWLEDGE HIDING IN TRANSACTIONAL DATABASES 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
      The hiding of sensitive knowledge in the form of frequent itemsets, has gained increasing attention over the past years. This paper highlights the process of border revision, which is essential for the identification of ...
    • Exact Knowledge Hiding through Database Extension 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
      In this paper, we propose a novel, exact border-based approach that provides an optimal solution for the hiding of sensitive frequent item sets by 1) minimally extending the original database by a synthetically generated ...
    • A free terrain model for trajectory k-anonymity 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2008)
      This paper introduces a privacy model for location based services that utilizes collected movement data to identify parts of the user trajectories, where user privacy is at an elevated risk. To protect the privacy of the ...
    • Hestia: Historically-enabled spatio-temporal information anonymity 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2010)
      Location-Based Services (LBSs) have long been established in several regions of the world to allow mobile users, equipped with positioning devices, access a set of spatially aware services. In this chapter, we introduce a ...
    • Hiding sensitive knowledge without side effects 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
      Sensitive knowledge hiding in large transactional databases is one of the major goals of privacy preserving data mining. However, it is only recently that researchers were able to identify exact solutions for the hiding ...
    • A hybrid approach to frequent itemset hiding 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2007)
      In this paper, we propose a novel, exact border-based approach that provides an optimal solution for the hiding of sensitive frequent itemsets by (i) minimally extending the original database by a synthetically generated ...
    • Identifying unsafe routes for network-based trajectory privacy 

      Gkoulalas-Divanis, A.; Verykios, V. S.; Mokbel, M. F. (2009)
      In this paper, we propose a privacy model that offers trajectory privacy to the requesters of Location-Based Services (LBSs), by utilizing an underlying network of user movement. The privacy model has been implemented as ...
    • An integer programming approach for frequent itemset hiding 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2006)
      The rapid growth of transactional data brought, soon enough, into attention the need of its further exploitation. In this paper, we investigate the problem of securing sensitive knowledge from being exposed in patterns ...
    • A k-anonymity model for spatio-temporal data 

      Zacharouli, P.; Gkoulalas-Divanis, A.; Verykios, V. S. (2007)
      The unprecedented growth In Location-Based Services (LBS) take-up along with the continuously increasing storage capabilities of modern systems, and have facilitated the collection of information related to users activities ...
    • A network aware privacy model for online requests in trajectory data 

      Gkoulalas-Divanis, A.; Verykios, V. S.; Bozanis, P. (2009)
      In this work, we propose a privacy model for online user requests on trajectory data in location based services by utilizing an underlying network of user movement. The privacy model has been implemented as a framework ...
    • A parallelization framework for exact knowledge hiding in transactional databases 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2008)
      The hiding of sensitive knowledge, mined from transactional databases, is one of the primary goals of privacy preserving data mining. The increased storage capabilities of modern databases and the necessity for hiding ...
    • PLOT: Privacy in location based services: An open-ended toolbox 

      Gkoulalas-Divanis, A.; Verykios, V. S.; Eleftheriou, D. (2009)
      The widespread adoption of Location Based Services (LBSs) coupled with recent advances in location tracking technologies, pose serious concerns to user privacy. As a consequence, privacy preserving approaches have been ...
    • Privacy and security in spatiotemporal data and trajectories 

      Verykios, V. S.; Damiani, M. L.; Gkoulalas-Divanis, A. (2008)
      The European directive 2002/58/EC requires providers of public communication networks and electronic communication services to adopt techniques to ensure data security and privacy. This directive states, among others, that ...
    • Privacy in spatiotemporal data mining 

      Bonchi, F.; Saygin, Y.; Verykios, V. S.; Atzori, M.; Gkoulalas-Divanis, A.; Kaya, S. V.; Savaś, E. (2008)
      Privacy is an essential requirement for the provision of electronic and knowledgebased services in modern e-business, e-commerce, e-government, and e-health environments. Nowadays, service providers can easily track ...
    • Privacy in trajectory data 

      Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
      In this era of significant advances in telecommunications and GPS sensors technology, a person can be tracked down to proximity of less than 5 meters. This remarkable progress enabled the offering of services that depend ...