In this paper, an efficient key management scheme based on public key elliptic curves signcryption (ECS) scheme for Wireless Sensor Networks (WSN) has been proposed. The proposed algorithm is compared with the scheme given in. For 250 cluster node, the saving in the total number of operations, key storage requirements, energy consumptions, and communication overhead are 75%, 96%, 23.79 m Joule, and 40% respectively compared with. The proposed protocol is efficient in terms of complexity, number of message exchange, computation, and storage requirements compared with. The proposed key management possesses not only provided confidentiality, authentication, integrity but also unforgeability.