A DK-PHBT Based Key Management Mechanism in Heterogeneous Wireless Sensor Networks

Abstract

In the security of wireless sensor network, the most important problem is how to distribute keys for the sensor nodes to establish a secure channel in an insecure environment. Because the sensor node has limited resources, for instance, low battery life and low computational power, the key distribution scheme must be designed in efficient manner. Recently many studies added a few highlevel nodes into the network, which called the Heterogeneous Sensor Network (HSN), and made some experiments to show that the security and performance can be enhanced. But these studies need a higher communication overhead for negotiation among sensor nodes in intergroup session key distribution. In addition, some studies used probability key pool distribution and nonpairwise key distribution, which causes lower connectivity and lower resilience. In this paper, we employ the Deployment Knowledge with Polynomial Hash Binary Tree (DKPHBT) to design a key management mechanism in HSN. A PHBT is a binary tree, built by shifting and hashing the coefficients of a bivariate polynomial. Using PHBT, the highlevel nodes in different group can negotiate each other for a shared polynomial without communication. The mechanism we proposed can ensure that each pair of nodes can share a pairwise key with lower computational costs and communicational costs in sensor nodes. In addition, because of establishing the deterministic pairwise keys in the system, the higher resilience ability and connectivity can be achieved.