Heraclitus : a LFSR-based stream cipher with key dependent structure

We describe Heraclitus as an example of a stream cipher that uses a 128 bit index string to specify the structure of each instance in real time: each instance of Heraclitus will be a stream cipher based on mutually clocked shift registers. Ciphers with key-dependent structures have been investigated and are generally based on Feistel networks. Heraclitus, however, is based on mutually clocked shift registers. Ciphers of this type have been extensively analysed, and published attacks on them will be infeasible against any instance of Heraclitus. The speed and security of Heraclitus makes it suitable as a session cipher, that is, an instance is generated at key exchange and used for one session.

Key predistribution scheme using finite fields and reed muller codes

Resource constraint sensors of a Wireless Sensor Network (WSN) cannot afford the use of costly encryption techniques like public key while dealing with sensitive data. So symmetric key encryption techniques are preferred where it is essential to have the same cryptographic key between communicating parties. To this end, keys are preloaded into the nodes before deployment and are to be established once they get deployed in the target area. This entire process is called key predistribution. In this paper we propose one such scheme using unique factorization of polynomials over Finite Fields. To the best of our knowledge such an elegant use of Algebra is being done for the first time in WSN literature. The best part of the scheme is large number of node support with very small and uniform key ring per node. However the resiliency is not good. For this reason we use a special technique based on Reed Muller codes proposed recently by Sarkar, Saha and Chowdhury in 2010. The combined scheme has good resiliency with huge node support using very less keys per node.

A health restructure, but the treatment misses some key points

The reforms need more focus on indigenous care, funding transparency and preventative medicine, writes Jim Hyde.

The relationship between coronary heart disease (CHD) and major depressive disorder (MDD) : key mechanisms and the role of quality of life

Various trials have been conducted evaluating depression management programs for patients with Coronary Heart Disease (CHD). However, to date, the most effective way to manage this co-morbidity in the real world setting remains unclear. To better understand the past successes and failures of previous trials and subsequently develop suitable interventions that target key components of health related quality of life (HRQOL) such as mental, physical and vocational functioning, we first need to understand the mechanisms underpinning the relationship between the two conditions. This paper will draw on the key literature in this field as identified by psychiatric, medical and social sciences databases (Cochrane Central Register of Controlled Trials, PubMed, OVID, Medline) available up to January 2012, with the aim to conduct a narrative review which explores: the aetiological relationship between depression and CHD; its association with HRQOL; the relationship between CHD, depression and vocational functioning; and the impact of depression treatment on these outcomes. Key recommendations are made regarding the management of this prevalent co-morbidity in clinical settings.

Using social network analysis to identify key child care center staff for obesity prevention interventions: a pilot study

Introduction. Interest has grown in how systems thinking could be used in obesity prevention. Relationships between key actors, represented by social networks, are an important focus for considering intervention in systems. Method. Two long day care centers were selected in which previous obesity prevention programs had been implemented. Measures showed ways in which physical activity and dietary policy are conversations and actions transacted through social networks (interrelationships) within centers, via an eight item closed-ended social network questionnaire. Questionnaire data were collected from (17/20; response rate 85%) long day care center staff. Social network density and centrality statistics were calculated, using UCINET social network software, to examine the role of networks in obesity prevention. Results. “Degree” (influence) and “betweeness” (gatekeeper) centrality measures of staff inter-relationships about physical activity, dietary, and policy information identified key players in each center. Network density was similar and high on some relationship networks in both centers but markedly different in others, suggesting that the network tool identified unique center social dynamics. These differences could potentially be the focus of future team capacity building. Conclusion. Social network analysis is a feasible and useful method to identify existing obesity prevention networks and key personnel in long day care centers.

Ecological determinism in Australia : tracing the legacy of McHarg downunder and its key precedents

Ecological planning, as advocated by Ian McHarg, filtered extensively through North America following the publication of Design with Nature (1965). The integrated design and planning approach was also advanced by numerous graduates of McHarg's studios at the University of Pennsylvania where this approach was extensively trialled and proven. While a clear synthesis and theoretical framework was articulated and reinforced through a plethora of projects, monographs, and articles, the majority of these perspectives were North American, lacked clarity about the translation of the approach into legal strategic and statutory planning instruments, nor shed light upon what transpired in Australia. This paper reviews the development of the Conservation Plan created for the southern Mornington peninsula in Victoria, Australia, as well as its intent, structure and internal workings as a successful model of ecological statutory planning, in the context of the wider WPRPA activities that draws directly from the McHarg theory. Known as the Conservation Plan for the southern Mornington Peninsula in Victoria, a revolutionary planning structure devised in the early 1970s by several Australian proponents. The Conservation Plan continues in operation today curating a high scenic valued landscape protecting it from intrusion from the growing metropolitan city of Melbourne thus fulfilling its objectives of landscape quality conservation whilst still permitting sympathetic building and land use growth. Contextually, the Conservation Plan appears to be only statutory equivalent translation of the approach internationally other than the Pinelands Commission planning processes in New Jersey.