Evaluating the energy-efficiency of key exchange protocols in wirelesssensor networks

Abstract

The evaluation of the energy-efficiency of applications and protocols is one of the most important issues in Wireless Sensor Networks (WSN). However, this is a time consuming and challenging task. Therefore, a realistic energy-efficiency evaluation is often neglected or oversimplified by using simple theoretical models or unsuited simulation tools. In this work, we evaluate the energy-efficiency of two specific key exchange protocols, an Elliptic Curve Diffie-Hellman with authentication (ECDH-ECDSA) and a Kerberos based approach, while using different duty-cycling MAC layer protocols. In our evaluation, we compare the results from a theoretical model with simulation results using the AVRORA+ simulation tool and real-world measurements in our WSN testbed SANDbed. Using three MAC layer protocols, Tiny-OS built in Low-Power-Listening as well as S-MAC and standard 802.15.4, we show that there are several important cross-layer effects that should be considered when performing an energy-efficiency evaluation. Furthermore, we argue, that there are several evaluation metrics like the absolute energy consumption per key exchange or one key exchange per measured time interval.

An energy benchmark for software updates on wireless sensor nodes

“…Power measurements for WSNs have been used to extend the capabilities of simulators (for example [19]), and work on energy evaluation [4] uses a mixture of theoretical, simulation, and real-world results to evaluate energy efficiency. But these results do not provide an absolute benchmark against which to evaluate protocols.…”