| Wireless Sensor Network (WSN) is an integrative intelligent information system, which can collect, transmit and deal with information. Wireless sensor network has many advantages, such as dynamic network, no need of fixed infrastructures and rapid reactions. However, it has disadvantages. For example, nodes in the network have limited resources and there is no central control. In addition, the topology of the network is dynamic. Aim at the high standard of security requirement for collecting information in military environment, this paper discusses the feasibility of the utility of public key authentication mechanism in wireless sensor network. On base of researches and analyses of existing public key encryption mechanisms used in sensor nodes and previous public key authentication schemes, a secure authentication scheme for WSN is proposed.In the proposed authentication scheme, a public key based partly distributed authentication model (PKPDAM) for cluster based sensor network is designed, which implements the advance deploy of authentication keys and distribution of public and secret keys for nodes by combining the node identifications with keys, and simplifies the management of keys and certificates by use of ECC combination public key technique. In PKPDAM, combined public key based authentication protocol, CPKAP, is designed to achieve the authentications and key agreements among cluster nodes. And an ECC-based Partly Distributed Authentication Protocol (PDAP) is designed to overcome the disadvantage that there is no trusted center in the network, which realizes the authentications and key agreements among cluster nodes and normal nodes. in view of the sensor node's limitation of computation, storage resources and energy, we make improvement on traditional public key certificate. The distributed authentication of nodes can be achieved by rebuilding the traditional public-key certificates.Formalized analyses show that CPKAP and PDAP can fulfill the high requirement of security of sensor networks in military environment. By network simulation, we come to the conclusion that compared with other public key authentication protocols, the proposed authentication protocols can effectively shorten the authentication delay and prolong the life time of the network. |
