An Enhanced Hybrid Key Management Protocol for Secure Multicast in Ad Hoc Networks

Colloque avec actes et comité de lecture. internationale.International audienceAn ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. This exibility in space and time induces new challenges towards the security infrastructure needed to support secure unicast and multicast communications. Especially, traditional group key management architectures meant for wired networks are not appropriate in such environment due to high dynamics and mobility of nodes. In this paper, we propose an enhanced hybrid key management protocol for secure multicast dedicated to operate in ad hoc networks. Built on a protocol called BAAL dedicated to key distribution in wired networks, our approach integrates threshold cryptography and the services of the AKMP protocol to deliver fast, efficient and mobility aware key distribution in a multicast service

'The brede of good & strong Horsis': zooarchaeological evidence for size change in horses from early modern London

Almost 200 horse bone measurements from 38 sites excavated across the city of London, dating to the period AD 1220–1900 were analysed. Results identified three main phases of size change: a reduction in size in the mid 14th to 15th century, and size increases in the mid 15th to 16th century and the 17th century. The decline in size testifies to the disruption of horse breeding in the wake of the Black Death, whilst the increases reflect purposeful attempts to increase the size of horses in England through a combination of regulated breeding and the importation of new bloodlines

A comparison of network and application layer multicast for mobile IPv6 networks

In this paper we compare Network (IP multicast) and Application Layer Multicast (ALM) under a specific assumption: end hosts are wireless devices using the Mobile IPv6 (MIPv6) protocol. This comparison has three main goals. First, we analyze the implications of running multicast in a mobile, wireless network using Mobile IPv6 (MIPv6). Second, we run a number of simulations to verify whether the network performance issues are different than in wired networks. Finally, using these results, we try to identify the factors that have the most significant impact on performance. Our results indicate that although ALM can be designed to work on top of a wireless network running MIPv6, there are a number of additional performance penalties beyond what occurs in wired networks. Essentially, the advantage of using IP multicast grows even stronger in mobile networks. Nevertheless, we recognize that there are significant barriers to ubiquitous network layer multicast and therefore believe that a more hybrid approach combining both IP multicast and ALM would offer the best performance

A.: A novel approach for transparent bandwidth conservation

Abstract. In this paper, we present a novel approach, stealth multicast, which offers a practical solution for the adoption of network-level IP multicast. Rather than focusing on a global scale such as with previous approaches, stealth multicast optimizes efficiency on a domain-wise scale. In short, stealth multicast dynamically combines redundant data payloads into virtual groups for multicast transmission across the domain. At the edge of the domain, the packets are converted back to unicast, thus keeping stealth multicast true to its namesake in that neither the user applications nor the external domain are aware of the presence of multicast. We present simulation studies to show the potential of stealth multicast.