Wireless sensor networks (WSNs) have attracted high interest over the last few decades in the wireless and mobile computing research community. Applications of WSNs are numerous and growing, including indoor deployment scenarios in the home and office to outdoor deployment in an adversary's territory in a tactical background. However, due to their distributed nature and deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their performance. This problem is more critical if the network is deployed for some mission-critical applications, such as in a tactical battlefield. Random failure of nodes is also very likely in real-life deployment scenarios. Due to resource constraints in the sensor nodes, a traditional security mechanism with high overhead of computation and communication is not feasible in WSNs. Design and implementation of secure WSNs is, therefore, a particularly challenging task. This book covers a comprehensive discussion on state-of-the-art security technologies for WSNs. It identifies various possible attacks at different layers of the communication protocol stack in a typical WSN and presents their possible countermeasures. A brief discussion on the future direction of research in WSN security is also included.

Securing data is crucial in a world where attackers will attempt to gain access to personal and business information that, for privacy reasons, we want to protect. Network topology can be used by an adversary to undermine a network. To protect this information, access to the data can be restricted. Sanitization, on the other hand, of the network topology information explores methods to mask the data in such a way to hide the network's characteristics while still providing an analyst data on which she can run statistics. There exists a tenuous balance between the need for privacy of the unsanitized network data and the accuracy of the analysis on the sanitized data.

Supra-molecular chemistry, conceptually founded as a research field in its own in the 1960s is a rapidly growing field at the borderline of several disciplines such as bio(organic) chemistry, material sciences and certainly the classical chemistry topics, i.e. (in) organic and physical chemistry. Selective binding of ions is an important area of supra-molecular chemistry research in terms of ion detection, transport and sensing. Currently, there is a surge of interest in the development of tailor-made sensor molecules, able to act as chromogenic sensors for a specific analyte as colorimetric sensors are simple-to-use diagnostic tools for sensing purposes that allow 'naked eye' detection of ions without resort to any spectroscopic instrumentation. In this book, the detailed photophysical studies of anthracene-9,10-diones bearing electron-rich coordinating sites at 1 / 1,8 or 1,4 positions for metal ions through color change have been elaborated. Also, the paradigm shift from selective to differential receptors has been used for single molecular receptor based simultaneous analysis of multiple analytes.