Date Added: May 2009
Early researches focused on the security of homogenous sensor networks. However, recent works have demonstrated that the presence of heterogeneous sensor nodes gives better performance than homogenous ones in terms of energy consumptions, storage overhead, and network connectivity. In this paper, the authors propose a hierarchical key management scheme named HERO which is based on random key pre-distribution. HERO aims to construct a secure tree instead of complete connected graph as in existing schemes. Thanks to this realistic assumption, their key management scheme reduces considerably the number of pre-loaded keys assigned to each node while maintaining high security level at the same time.