ACE Seminar: Geo-indistinguishability: A Principled Approach to Location Privacy

Speaker: Dr Kostas Chatzikokolakis

Date/Time: 13-Oct-2016, 16:00 UTC




In this talk I will present our ongoing project aimed at protecting the privacy of the user when dealing with location-based services. The starting point of our approach is the principle of geo-indistinguishability, a formal notion of privacy that protects the user's exact location, while allowing approximate information -- typically needed to obtain a certain desired service -- to be released.

I will give a quick overview of our results in this area: a generic efficient mechanism to sanitize locations with reasonable utility; a custom-built mechanism for a limited set of locations but providing optimal utility; a method
to limit the privacy degradation in case of repeated use of the mechanism; a technique to construct elastic metrics for location privacy taking into account the semantics of each location.

Finally, I will present Location Guard, a web browser extension that provides location privacy when using the HTML5 geolocation API. The extension, available for both desktop (Chrome, Firefox, Opera) and mobile (Firefox) browsers, has reached considerable popularity since its release, with more than 60k active users.


Kostas Chatzikokolakis is a CNRS researcher at the Ecole Polytechnique of Paris, France.

He studied computer science and telecommunications at the National University of Athens. He did a masters degree and a Ph.D. in computer science (awarded in 2007) at the Ecole Polytechnique of Paris, France. From 2007 to 2010 he was a post-doctoral researcher at Oxford University, UK, and at the Technical University of Eindhoven, The Netherlands.

His research interests include security and privacy (in particular quantitative information flow and differential privacy), probabilistic process calculi and information theory. He has published more than 40 research papers and has been in the PC of 33 international conferences and workshops.

His teaching experience includes master courses on Privacy as well as on Concurrency at the Parisian Master of Research in Computer Science (MPRI), a master course on security protocols at the Information Security Technology master at TU/e, and summer school courses on quantitative information flow and differential privacy at Cali, Colombia and Rio Cuarto, Argentina.

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