The Impact of Operating Frequency on Power Optimization for Wireless Sensor Networks Security

Security is a key consideration when deploying wireless sensor networks (WSNs). Since the battery life confines the lifetime of a sensor node, power consumption is normally set as the first priority in developing security solutions. Due to the hardware resources constraint, lightweight cryptographic primitives are often implemented on sensor networks for ultra low power consumption. Apart from the complexity of cryptographic algorithms, the method of implementing them is another crucial aspect that impacts the power efficiency of WSN security. Previous research in security implementation techniques mainly aimed at reducing the power of implementing devices or accelerating the primitive execution. This paper points out that the operating frequency could be a significant factor influencing the overall power consumption of a target security solution, which has been unnoticed before. Based on this finding a novel concept is proposed to optimize the security solution in terms of power. An empirical platform is setup on top of FPGA devices to investigate the feasibility of this idea in practice. This study concludes that a further power optimization can be obtained by adjusting operating frequency even though implementing hardware and programming technique are fixed for a particular security.