In the first part of this talk, I will go over our methods on establishing a secure group communications framework for resource constrained, infrastructure-less networks, optimizing a number of metrics of interest, from the point of view of Key Management (KM). Our work focuses on the design of efficient, robust, group KM schemes, capable of distributed operation where key infrastructure components are absent or inaccessible, that accomplish the following: (a) better performance than this of existing schemes for similar environments, (b) successfully handle network dynamics and failures, in networks of large number of nodes. We present algorithms and protocols for handling membership changes, disruptions and failures with low overhead for initial key establishment or steady state. In an effort to reduce the suboptimal performance of protocols when executed without topological considerations, underlying routing is integrated into the design by the definition of topology oriented communication schedules, using novel lightweight heuristics.

In the second part of the talk, we focus on improving the expected user performance metrics associated with flooding link state routing information. We compare existing schemes such as this of Multi-Point Relays with our new approach which is based on the use of Connected Dominating Set (CDSs). We develop asymptotic analytical bounds for the approaches under study, and conduct a comparative performance evaluation to determine under which conditions one approach is more suitable than another. We only introduce the Hexagon-based representative of our models - CDS-HEX - as it provides the lowest routing overhead among other properties. We describe our heuristics to generate CDS-HEX in a distributed fashion from a random placement of nodes, so that it simulates the described analytical model as close as possible.