Secure group communication schemes for dynamic heterogeneous distributed computing

Nowadays Sensor Networks and Ad Hoc Networks are widely used communication facilities, mainly because of their many application settings. Again, though above types of network are paradigms of communication widespread and well-established in the state of the art, however, they turn out to be among the most important concepts underlying the modern and increasingly expanding User-Centric Networks, which can be used to build dynamic middleware services for heterogeneous distributed computing. In this way, can be addressed the strong dynamic behavior of user communities and of resource collections they use.In this paper we focus our attention on key predistribution for secure communications in those types of networks. In particular, we first analyze some schemes proposed in the literature for enabling a group of two or more nodes to compute a common key, which can be used later on to encrypt or authenticate exchanged messages. The schemes we have chosen are well representative of different design strategies proposed in the state of the art. Moreover, in order to find out under which conditions and in which settings a scheme is more suitable than others, we provide an evaluation and a performance comparison of those schemes. Furthermore, we look at the problem of identifying optimal values for the parameters of such schemes, with respect to a certain desirable security degree and reasonable security assumptions. Finally, we extend one of those schemes, showing both analytically and through experiments, the improvement the new scheme provides in terms of security compared to the basic one.