Scalar Multiplication of a Dynamic Window with Fuzzy Controller for Elliptic Curve Cryptography

Elliptic curve cryptography (ECC) provides solid potential for wireless sensor network security due to its small key size and its high security strength. However, there is a need to reduce key calculation time to satisfy the full range of potential applications, in particular those involving wireless sensor networks (WSN). Scalar multiplication operation in elliptical curve cryptography accounts for 80% of key calculation time on wireless sensor network motes. In this paper, two major contributions are made: (a) we propose an algorithm based on 1´s complement subtraction to represent scalar in scalar multiplication which offer less Hamming weight and will significantly improve the computational efficiency of scalar multiplication; and (b) we present a fuzzy controller for dynamic window sizing to allow the program to run under optimum conditions by allocating available RAM and ROM at the sensor node within a wireless sensor network. The simulation results showed that the average calculation time decreased by approximately 15% in comparison to traditional algorithms in an ECC wireless sensor network.