Performance Analysis of Novel Randomly Shifted Certification Authority Authentication Protocol for MANETs

The provision of security in mobile ad hoc networks is of paramount importance due to their wireless nature. However, when conducting research into security protocols for ad hoc networks it is necessary to consider these in the context of the overall system. For example, communicational delay associated with the underlying MAC layer needs to be taken into account. Nodes in mobile ad hoc networks must strictly obey the rules of the underlying MAC when transmitting security-related messages while still maintaining a certain quality of service. In this paper a novel authentication protocol, RASCAAL, is described and its performance is analysed by investigating both the communicational-related effects of the underlying IEEE 802.11 MAC and the computational-related effects of the cryptographic algorithms employed. To the best of the authors' knowledge, RASCAAL is the first authentication protocol which proposes the concept of dynamically formed short-lived random clusters with no prior knowledge of the cluster head. The performance analysis demonstrates that the communication losses outweigh the computation losses with respect to energy and delay. MAC-related communicational effects account for 99% of the total delay and total energy consumption incurred by the RASCAAL protocol. The results also show that a saving in communicational energy of up to 12.5% can be achieved by changing the status of the wireless nodes during the course of operation. Copyright (C) 2009 G. A. Safdar and M. P. O'Neill (nee McLoone).

The policy context of leaving care services: A case study of Northern Ireland

The transition of foster youth from state care to independent living has received increased research, practice, and policy attention in the United States and in many other countries. Most contributions to this literature have focused on documenting poor outcomes across various dimensions of need in the young people's lives whereas little attention has been given to the policy context in which the responses to those needs are being developed. In this article, we argue that there is a pressing need for better understanding of how the policy context can both promote and impede the development of appropriate services. To illustrate our argument, we use Northern Ireland as a policy case study both because of recent initiatives underway there in regard to youth transitions from state care and because of the heightened political sensibilities associated with it as a society. We draw attention to the socio-political historical context, a number of intersecting social policies, and the place of social work as a key occupation involved in delivering service improvements. We conclude by suggesting that this case study not only highlights the need to address similar aspects of the policy on youth transition frorn state care in the United States but also demonstrates the benefits of reflecting on policy development and implementation elsewhere in the world.