Publications de Reza Shokri | EPFL Graph Search

Initialization Matters: Privacy-Utility Analysis of Overparameterized Neural Networks

Volkan Cevher, Fanghui Liu, Zhenyu Zhu, Reza Shokri

We analytically investigate how over-parameterization of models in randomized machine learning algorithms impacts the information leakage about their training data. Specifically, we prove a privacy bound for the KL divergence between model distributions on ...

2023

A Predictive Model for User Motivation and Utility Implications of Privacy-Protection Mechanisms in Location Check-Ins

Jean-Pierre Hubaux, Kévin Clément Huguenin, Igor Bilogrevic, Reza Shokri, Italo Ivan Dacosta Petrocelli, Joana Catarina Soares Machado, Stefan Mihaila

Location check-ins contain both geographical and semantic information about the visited venues. Semantic information is usually represented by means of tags (e.g., “restaurant”). Such data can reveal some personal information about users beyond what they a ...

2018

Quantifying Interdependent Privacy Risks with Location Data

Jean-Pierre Hubaux, Reza Shokri, Kévin Clément Huguenin, Mathias Jacques Jean-Marc Humbert, Alexandra-Mihaela Olteanu

Co-location information about users is increasingly available online. For instance, mobile users more and more frequently report their co-locations with other users in the messages and in the pictures they post on social networking websites by tagging the ...

Ieee Computer Soc2017

Predicting Users' Motivations behind Location Check-Ins and Utility Implications of Privacy Protection Mechanisms

Jean-Pierre Hubaux, Kévin Clément Huguenin, Igor Bilogrevic, Reza Shokri, Stefan Mihaila

Location check-ins contain both geographical and semantic information about the visited venues, in the form of tags (e.g., “restaurant”). Such data might reveal some personal information about users beyond what they actually want to disclose, hence their p ...

2015

Quantifying the Effect of Co-location Information on Location Privacy

Jean-Pierre Hubaux, Kévin Clément Huguenin, Reza Shokri, Alexandra-Mihaela Olteanu

Mobile users increasingly report their co-locations with other users, in addition to revealing their locations to online services. For instance, they tag the names of the friends they are with, in the messages and in the pictures they post on social networ ...

Springer-Verlag Berlin2014

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

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

Quantifying and Protecting Location Privacy

Reza Shokri

Recent developments in information and communication technologies have been profound and life-changing. Most people are now equipped with smart phones with high computation power and communication capabilities. These devices can efficiently run multiple so ...

EPFL2013

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

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