  Limited resources (such as energy, computing power, storage, and so on) make
it impractical for wireless sensor networks (WSNs) to deploy traditional
security schemes. In this paper, a hierarchical key management scheme is
proposed on the basis of identity-based encryption (IBE).This proposed scheme
not only converts the distributed flat architecture of the WSNs to a
hierarchical architecture for better network management but also ensures the
independence and security of the sub-networks. This paper firstly reviews the
identity-based encryption, particularly, the Boneh-Franklin algorithm. Then a
novel hierarchical key management scheme based on the basic Boneh-Franklin and
Diffie-Hellman (DH) algorithms is proposed. At last, the security and
efficiency of our scheme is discussed by comparing with other identity-based
schemes for flat architecture of WSNs.
