General Anonymous Key Broadcasting via Lagrangian Interpolation
            Lukasz Krzywiecki, Miroslaw Kutylowski, Maciej Nikodem
                     Wroclaw University of Technology

We provide a broadcast encryption scheme, namely a modification of the classical 
Lagrangian interpolation in the exponent, that provides
significantly more privacy. A pseudonym used in the transmission
does not necessarily indicate that the corresponding user has been
excluded from the set of entitled users, which in turn 
disables analysis of users' behaviour. Moreover, communication overhead
is independent on the dynamics of the system.