Dec. 2013. During the first year, the activity of PRINCESS has focused on the following main directions:
(1) The study of an extention of the notion of differential privacy. The property of differential privacy implicitly relies on the Hamming distance between databases. We have extended it to arbitrary metrics, thus obtaining a principle that can be applied to any domain equipped with a notion of distance. The results of this study have appeared in the symposium PETS 2013.
(2) We have applied the generalized notion of differential privacy to the specific case of geographic data, and we have developed a method that allows to use location-based services while maintaining a certain degree of privacy. The results of this work have appeared in the conference CCS 2013.
(3) We have continued our investigation of the relation between differential privacy and quantitative information flow. This work has involved researchers from all the three partners sites: INRIA, University of Pennsylvania, and Florida International University. The paper containing the results of this study has been accepted for publication on the Journal of Computer Security.
(4) There is growing recognition that different models of adversaries lead to different leakage measures. We have investigated the g-leakage measures, which use gain functions g to model the operational scenario in which an adversary operates, and the criteria for evaluating the effectiveness of its attacks. We have shown that the strong g-leakage ordering and composition refinement coincide on abstract channels, giving us a partial order that has both structural and leakage-testing significance.