In many parallel and distributed applications broadcasting represents a natural way of communication between processes/objects/actors. In addition mobility is often mandatory, as for instance, for the development of ad-hoc networks applications. The fusion of these two concepts into one unique and coherent model of concurrency, represents a great interest for the development of such classes of applications together with appropriate programming models and languages. An original model that combines mobility and selective broadcasting has been developed by Ene and Muntean: the b?-calculus. The "Mobile Ambients" by Gordon and Cardelli, represents also, among others, an interesting framework for mobility and ubiquity of applications. The goal of this paper is to propose a model for Broadcasting Secure Systems that we consider to be more appropriate for ad-hoc networks and ubiquitous applications, reinforcing the mobility and security aspects.