The Research Of Key Management Schemes In Wireless Sensor Networks

Wireless Sensor network (WSN) is a new type network composed by a largenumber of Wireless Sensor, and these nodes are deployed in monitoring area toperception and gather information. At present, sensor network has been applied widelyin such areas as data collection, military surveillance, environmental monitoring,medical applications, intelligent transportation, robot control, remote control ofdangerous areas.Usually, Wireless Sensor nodes have the advantages of small size, having cheapprice, but have certain limitations in the battery capacity, memory capacity, computingpower and communication range, etc., so the sensor nodes are always vulnerable tovarious attacks. Therefore, the security of sensor network has become a priority. Thecommunication with the encryption mechanism can achieve certain security.Considering that the captive sensor nodes may reveal the key information they contains,while in the wireless sensor network which is composed of a large number of sensornodes, it is hard to prevent the sensor nodes to be captured. Therefore, the designed keymanagement scheme must be able to resist capture attacks.For centralized wireless sensor network, this paper puts forward an keymanagement scheme based on grid deployment model, which is combined with Blomscheme. The deployment area is divided into some hexagonal grid areas which are notoverlap with each other, and the base station distributes different key space for eachhexagonal grid area, which makes any adjacent hexagonal grid only shares a secret keyspace while not adjacent hexagonal grids do not have the same key space. Thenaccording to the deployment knowledge of sensor nodes and the known grid area,allocates key space information for these nodes. After sensor nodes deployed, onlysensor nodes between the neighboring grid areas could establish a session key accordingto the shared key information, while the others cannot establish communication keydirectly. Compared with the existing random key pre-distribution scheme based on keypool, key pre-distribution scheme of multi-key space which is based on Blom matrix,the proposed scheme makes the whole sensor network with full connectivity; reduce thememory consumption to store the key information. In addition, the ability of resistanceto random attack and area attack of the wireless sensor nodes has been enhanced greatly.In view of the wireless sensor network with a hierarchical structure, this paper proposes a hybrid key management scheme based on quadratic form. The target areaunder monitoring is divided into multiple square areas which do not overlap with eachother. Sensor nodes in each area include cluster nodes and member nodes. Any twosensor nodes in the same area set up the session key to each other by the improvedBlom scheme, which is according to the key information stored in the pre-allocatedprocess. The session key between different regions can only be established by clusternodes. Firstly, calculate multiple asymmetric quadratic eigenvalues and correspondingeigenvectors, and then the eigenvalue and eigenvector are orthogonal transformed, andget the orthogonalization information after united. Finally, cluster nodes realize identityauthentication through the exchange of orthogonalization information between them,and form the communication keys between the cluster nodes. Performance analysisshows that compared with the existing key management schemes, the proposed schemehas the full connectivity, and has significant improvement in communication overhead,storage consumption and safety, etc.