Abstract: A new key management and authentication model for Ad hoc networks is proposed. In this model, the elliptic curve combined public key is applied, and the trusted authentication center support is needed only in the key initialization phase. In the operation phase, the self-organized public／private key update, revocation, and shared-private-key-matrix update are implemented with threshold cryptograph. An authentication and key agreement protocol is designed. The interlocutor’s public key is produced by computing, and two-time certificate transmission and verification are therefore reduced in the protocol. Compared with the certificate-based and the identity-based models, the new model is more secure, flexible and efficient. And it is more suitable for the self-organized and resource-constrained features of Ad hoc networks.

Key words: combined public key, threshold cryptograph, Ad hoc network, key management, authentication