Abstract: Mobile Ad hoc Network (MANET) is a collection of wireless infrastructure less network. The topology of the network changes continuously. Due to the dynamic structure of MANETs, they are prone to various types of attacks. The traditional security solutions for MANETs are inadequate, hence security should be maintained at all the levels. Many key management schemes for MANETs are presented to solve various security problems. Usually the cryptography techniques are used for secure communications in wired and wireless networks. Identities (ID)-based cryptography with threshold secret sharing, ECC and Bilinear Pairing computation are popular approaches for the key management design. The task of key management includes keys for generation, distribution and maintenance. Key maintenance includes the procedures for key storage, key update, key revocation. Thus the security is enhanced at various levels which prevent strong malicious attacks. In this paper, we adopt these approaches to construct tree structure and cluster structure ad hoc network and then give out a three-level security communication ad hoc network.

Keywords: MANET, wireless security, Elliptic Curve Cryptography, ID-based key management.