Secure group communication systems become more and more important in many emerging network applications. For a secure group communication system, an efficient and robust group key management approach is essential. In this paper, a new group key management approach with a group controller GC using the theory of hyper-sphere is developed, where a hyper-sphere is constructed for the group and each...

Privacy is a basic human need. It is anthropologically and psychologically rooted in the sense of shame and the need for bodily integrity, personal space, and intimacy in interpersonal relationships. Especially in modern Western cultures, it is understood as a necessary condition for individual autonomy, identity, and integrity (Altman 1975; Westin 1967; see also Margulis, this volume, Chap. 2)...

In this article two distinct but related questions are addressed. First, can the politics of ecology be articulated in terms of citizenship? An affirmative answer is given to this question, and an outline of ‘ecological citizenship’ is presented. This gives rise to the second question: how does ecological citizenship affect the idea of citizenship itself? This question is answered through the a...

Environmental problems in the energy system often originate from everyday activities and choices. Everyday activities in the home are part of the private sphere, that can be contested in relation to energy policies. This article discusses the public-private divide in energy policies and how Swedish municipal energy consultants understand the divide. By analyzing the actions of energy consultant...

Chapter 6: Varieties of the Public Sphere To this point, we have encountered changes, as well as continuity, in European politics, economics, society, and thought. Each of these developments contributed to a transformation that some consider the most fundamental transformation of the century -the emergence, between the state sector and private economic sphere, of autonomous institutions of civi...

User-controlled identity management systems assist individuals in managing their private sphere. An individual’s privacy can be supported by transparency on processing of personal data. After giving an overview on transparency properties as well as its relation to privacy and data protection regulation, this text introduces different transparency tools: Prior to an interaction, information on t...