Providing security in energy harvesting sensor networks

In this work, we study the adaptability of well known cryptography algorithms to energy harvesting wireless sensor networks. We are particularly interested in algorithms that have the ability to adapt to varying power in such networks. Our investigations and implementation on hardware platforms indicate that it is optimal to precompute a few key stream bytes, store in memory and later used during the time when the system is low on harvested power level. Our demonstrable setup shows using a precomputed key stream can decrease the energy consumption by 14%. We have implemented the Trivium stream cipher for two different microcontrollers, the MSP430 and the AVR ATmega1281 and show the performance results for these implementations. We have implemented an algorithm based on universal hash functions to provide message authentication with the assistance of stream ciphers. We show that this authentication algorithm has exciting properties for energy harvesting system and more generally for resource constrained devices.