Towards Adaptable Security for Energy Efficiency in Wireless Sensor Networks

— Modern sensors are portable, embeddable, they offer multiple connectivity options and enough processing power that allows the performance of advanced operations. Multiple sensors can be used together forming a wireless sensor network (WSN). Ubiquitous WSNs are expected to play a significant role in the future, assisting users in their everyday life. In this paper we present an intriguing application of WSNs: health monitoring of hospital patients. We focus on the security aspects of this application and identify security threats and requirements. Moreover, we argue that existing security solutions are energy hungry, therefore they are inappropriate for WSNs and we propose a new security design approach: adaptable security. Our design approach advocates that security mechanisms should be able to adapt their complexity by ranking the security requirements of each operation, achieving this way better energy efficiency. I. INTRODUCTION Wireless sensors are expected to become a core component of future ubiquitous networks. As technology evolves, sensors become smaller, smarter, with even more processing and interconnection capabilities and their application field becomes wider and wider. Sensors are already embedded in daily usage devices—such as smartphones—and the fact that they are being used on regular basis reveals their great potentials. Due to their size, sensors, can be very pervasive which combined with their advanced sensing and inteconnection features may jeopardize user's privacy. On the other hand security mechanisms require complex computations which lead to increased energy consumption and therefore limit the operational scope of sensors. As security mechanisms have not been designed with energy efficiency in mind, they cannot always be applied in sensor networks without firstly being reconsidered and modified. In this paper we introduce the concept of adaptable security, i.e, how security mechanisms can be adapted in order to satisfy the security and energy requirements of a specific application. The use case application for this paper is the health monitoring of hospitals' inmates