Comete-Parsifal Seminar Thu Jun 21, 15:00 LIX, Ecole Polytechnique Salle de Reunion, LIX http://www.lix.polytechnique.fr/comete/seminar/ Lien pour accéder au campus : http://www.polytechnique.edu/accueil/vie-sur-le-campus/acceder-au-campus/ Link to reach the campus: http://www.polytechnique.edu/home/life-on-campus/arriving-on-campus/ Title: Measuring Information Leakage using Generalized Gain Functions. Speaker: Kostas Chatzikokolakis. Abstract: This talk introduces g-leakage, a rich generalization of the min-entropy model of quantitative information flow. In g-leakage, the benefit that an adversary derives from a certain guess about a secret is specified using a gain function g. Gain functions allow a wide variety of operational scenarios to be modeled, including those where the adversary benefits from guessing a value close to the secret, guessing a part of the secret, guessing a property of the secret, or guessing the secret within some number of tries. I will discuss important properties of g-leakage, including bounds between min-capacity, g-capacity, and Shannon capacity. Moreover I will discuss a connection between a strong leakage ordering on two channels, C1 and C2, and the possibility of factoring C1 into C_2C_3, for some C3. Based on this connection, I will propose a generalization of the Lattice of Information from deterministic to probabilistic channels