Cryptographic Overhead in Sensor Networks with HFE Scheme

In this paper, the energy consumption of Hidden field equation (HFE) multivariate scheme in wireless sensor networks (WSNs) has been examined. Security provisioning in a WSN requires balancing between two conflicting goals - security strength and resource efficiency. Most of the cryptosystems with security strength required in a WSN are highly resource intensive. Cryptographic operations consume processor power, time and memory space for storage of intermediate and final output. The cryptographic bits also constitute communication overhead that induces delay and decrease in throughput. To lessen the load on the resource constrained WSN without compromising security, HFE multivariate scheme is proposed. It is a type of multivariate cryptosystems in which linear equations are solved to obtain successive sets of central variables. The small number of operations and limited memory requirements make this scheme a potential candidate for security provisioning in WSN. Analysis shows that the scheme can be implemented on resource constrained sensor nodes. And cryptographic overheads induced by HFE scheme are within the tolerable limits of WSN applications.