A hierarchical key assignment scheme is a method to assign encryption keys to a set of classes in a partially ordered hierarchy, in such a way that the key of a higher class can be used to derive the keys of all classes lower down in the hierarchy.
In this talk, we present definitions of security with respect to key indistinguishability and against key recovery under attacks carried out by static and adaptive polynomial-time adversaries. Hence, we characterize the resulting definitions, by exploring the relations between them. Motivated by the need of designing provably-secure schemes, we propose different constructions for key assignment schemes. All constructions are provably-secure and can be efficiently implemented.
This talk covers joint work with Prof. Giuseppe Ateniese, Prof. Alfredo De Santis, and Dott. Barbara Masucci that will appear at the 13th ACM Conference on Computer and Communications Security (CCS) in November, 2006.
Anna Lisa Ferrara is a postdoc at the Dipartimento di Informatica ed Applicazioni "Renato Capocelli" of the University of Salerno. Her research interests include algorithms and cryptography.
In 2002, she received the Laurea degree in Computer Science from the University of Salerno. From November 2002 to November 2005 she was a PhD student in Computer Science, under the supervision of Prof. Alfredo De Santis.
From September 2004 to May 2005 she was a visiting researcher at the Centre for Applied Cryptographic Research, in the Department of Computer Science of the University of Waterloo, Ontario, Canada, under the supervision of Prof. Douglas Stinson. In 2006 she received the Dottorato di Ricerca (PhD) degree in Computer Science from the University of Salerno, discussing a thesis on Cryptography, whose title is "On Access Control Policies and Key Assignment Schemes", supervised by Prof. Alfredo De Santis.