Security mechanisms in partially isolated networks

A challenged network is a network subject to difficult operational constraints, like disrupted links and high delays. An example is a mobile ad hoc network where the nodes communicate without infrastructure support. Specifics of such networks are the consequence of intermittent access to (or complete lack of) infrastructure and partial isolation of the network nodes from each other. Partial isolation of the nodes aggravates resource scarcity. In this work we investigate (1) security and privacy, as well as (2) resource management, in these networks. Our thesis is that in partially isolated networks security and privacy, on the one hand, and resource management, on the other, are closely related and tend to influence each other. This dissertation includes nine publications. Their summaries are grouped in two chapters. The first, Chapter 2, is about security and privacy issues and also the question of congested buffer management, which we approach via adversarial scenario. % In the second, Chapter 3, we consider better utilization of the scarce contact time between the network nodes via message fragmentation when there are intermittent transmission opportunities. Part of the work comprising this dissertation had industrial impact: I have contributed to the Generic Authentication Architecture standard of 3GPP, described in publication II; and the "Equal Subdomains" technique found in publication IV was included of the Nokia Awarenet platform.