An energy efficient encryption method for secure dynamic WSN.

Clustering methods have been developed to improve network life of wireless sensor network WSN, yet the dynamic nature of sensor clusters and limited memory and processing power make security a much more challenging problem, and most conventional cryptography methods are ill suited to WSNs. In this paper, we propose a novel encryption method to secure data transmission in WSN with dynamic sensor clusters. Our method leverages elliptic curve cryptography algorithm to generate binary strings for each sensor and combines with node ID, distance to the cluster head, and the index of transmission round to form unique 176-bit encryption keys. Using exclusive OR, substitution, and permutation operations, encryption and decryption are achieved efficiently. Compared with the state-of-the-art methods, our simulation results demonstrated that the proposed method exhibited much improved network lifetime and reduced the energy consumption most evenly among all sensor nodes. More importantly, it overcame many security attacks including brute-force attack, HELLO flood attack, selective forwarding attack, and compromised cluster head attack. Copyright © 2016 John Wiley & Sons, Ltd.