Performance trade-offs of encryption algorithms for Wireless Sensor Networks

Several security mechanisms have been introduced to address the need for reliable and efficient security schemes in resource limited Wireless Sensor Networks (WSNs). Limitations in processing speed, battery power, bandwidth and memory constrain the applicability of existing cryptographic Algorithms in WSNs. Accordingly, it is necessary to assess the performance tradeoffs of the cryptographic algorithms to provide a better understanding of the security cost. In this paper, we have studied three block cipher algorithms: Advanced Encryption Standard (AES), RC5, and RC6. We have measured and compared their memory and energy consumption in the Mica2 sensor motes. Experimentation results show that AES has higher memory and energy requirements than RC5 and RC6. RC6 has higher operation time and power consumption while RC5 is the most time- and energy-efficient block cipher and thus the best cipher solution for devices with limited resources.