Publications by Georgios Theodorakopoulos

Hiding in the Mobile Crowd: Location Privacy through Collaboration

Jean-Pierre Hubaux, Panagiotis Papadimitratos, Reza Shokri, Ehsan Kazemi, Georgios Theodorakopoulos

Location-aware smartphones support various location-based services (LBSs): users query the LBS server and learn on the fly about their surroundings. However, such queries give away private information, enabling the LBS to track users. We address this probl ...

Ieee Computer Soc2014

Prolonging the Hide-and-Seek Game: Optimal Trajectory Privacy for Location-Based Services

Jean-Yves Le Boudec, Jean-Pierre Hubaux, Reza Shokri, Carmela González Troncoso, Georgios Theodorakopoulos

Human mobility is highly predictable. Individuals tend to only visit a few locations with high frequency, and to move among them in a certain sequence reflecting their habits and daily routine. This predictability has to be taken into account in the design ...

2014

Protecting Location Privacy: Optimal Strategy against Localization Attacks

Jean-Yves Le Boudec, Jean-Pierre Hubaux, Reza Shokri, Carmela González Troncoso, Georgios Theodorakopoulos

The mainstream approach to protecting the location-privacy of mobile users in location-based services (LBSs) is to alter the users' actual locations in order to reduce the location information exposed to the service provider. The location obfuscation algor ...

2012

Traps and Pitfalls of Using Contact Traces in Performance Studies of Opportunistic Networks

Jean-Yves Le Boudec, Nikodin Ristanovic, Georgios Theodorakopoulos

Contact-based simulations are a very popular tool for the analysis of opportunistic networks. They are used for evaluation of networking metrics, for quantifying the effects of infrastructure and for the design of forwarding strategies. However, little evi ...

Ieee2012

Selfish Response to Epidemic Propagation

Jean-Yves Le Boudec, Georgios Theodorakopoulos

An epidemic spreading in a network calls for a decision on the part of the network members: They should decide whether to protect themselves or not. Their decision depends on the trade off between their perceived risk of being infected and the cost of bein ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Quantifying Location Privacy

Jean-Yves Le Boudec, Jean-Pierre Hubaux, Reza Shokri, Georgios Theodorakopoulos

It is a well-known fact that the progress of personal communication devices leads to serious concerns about privacy in general, and location privacy in particular. As a response to these issues, a number of Location-Privacy Protection Mechanisms (LPPMs) ha ...

Ieee Computer Soc Press, Customer Service Center, Po Box 3014, 10662 Los Vaqueros Circle, Los Alamitos, Ca 90720-1264 Usa2011

Quantifying Location Privacy: The Case of Sporadic Location Exposure

Jean-Yves Le Boudec, Jean-Pierre Hubaux, Reza Shokri, Georgios Theodorakopoulos

Mobile users expose their location to potentially untrusted entities by using location-based services. Based on the frequency of location exposure in these applications, we divide them into two main types: Continuous and Sporadic. These two location exposu ...

Springer-Verlag Berlin2011

Collaborative Location Privacy

Jean-Pierre Hubaux, Panagiotis Papadimitratos, Reza Shokri, Georgios Theodorakopoulos

Location-aware smart phones support various location-based services (LBSs): users query the LBS server and learn on the fly about their surroundings. However, such queries give away private information, enabling the LBS to identify and track users. We addr ...

2011

Preserving Privacy in Collaborative Filtering through Distributed Aggregation of Offline Profiles

Jean-Pierre Hubaux, Reza Shokri, Pedram Pedarsani, Georgios Theodorakopoulos

In recommender systems, usually, a central server needs to have access to users' profiles in order to generate useful recommendations. Having this access, however, undermines the users' privacy. The more information is revealed to the server on the user-it ...

ACM2009

Adaptive Message Authentication for Vehicular Networks

Jean-Yves Le Boudec, Jean-Pierre Hubaux, Nikodin Ristanovic, Panagiotis Papadimitratos, Georgios Theodorakopoulos

Public key cryptography can introduce significant processing delays in vehicular communication platforms. This can lead to serious performance issues, especially in the case of multi-hop Inter-Vehicle Communication. In this paper we propose Adaptive Messag ...

ACM2009