The effect of symmetric block ciphers on WSN performance and behavior

Nowadays Wireless Sensor Networks are increasingly accepted as a reliable solution to highly demanding and critical application scenarios such as military and medical environments, where security support is an absolute prerequisite. However, supporting security implies the execution of cipher algorithms posing significant overheads on WSN nodes, which suffer from scarce resource availability. Moreover, the system wide overheads imposed by requirements related to network performance and behavior are not adequately addressed in current literature. In that direction, this paper intends to evaluate these effects for critical network parameters. The results presented are based on existing results reported in literature measurements concerning the performance overhead imposed by widely utilized encryption algorithms that have been developed for prominent WSN platforms. To evaluate the measurements, the execution performance of three popular cipher algorithms, has been integrated in Omnet++/MiXiM, a well known and widely utilized WSN network simulator. As part of this work, critical insights are provided concerning the system wide effect of deploying security algorithms which are not taken into account when focusing solely in the security algorithm measurements. Furthermore, important trade-offs are provided both qualitatively and quantitatively.