Research On Key Management In Wireless Sensor Networks

Recent advancement in wireless communications and electronics has enabled the development of low-cost sensor networks. wireless sensor networks made up by the number of sensor nodes are used to collect and transport information. Providing security in wireless sensor networks is challenging due to all the characteristics of these networks, such as limitations of power, computation capability and storage resources. A solid key management frame work is one of the most crucial technologies to achieving secure infrastructure in wireless sensor networks. However because of the restricted resources and lacking of certification center, the conventional schemes maybe impractical in wireless sensor networks. Many researchers do much work on key management in wireless sensor networks and obtain great achievement. However, some issues on key agreement in wireless sensor networks are not resolved effectively. It is necessary to do further research on these issues.Blundo protocol is a famous predistribution scheme for wireless sensor networks. A symmetric bivariate polynomial of degree t is used and its shares are distributed among the parties in this scheme to construct shared keys. In order to ensure resilience to nodes compromising, the degree t of the symmetric bivariate polynomial used in Blundo scheme should large enough. But the value of the degree t is larger; the consumption of the energy is bigger. To solve this problem, a key predistribution scheme based on hierarchical grid is proposed for wireless sensor networks. Using hierarchical gird and Blundo scheme, in the proposed scheme, different symmetric bivariate polynomials can be choose to establish different shared keys, so that this scheme ensures resilience to nodes compromising which enhanced the security of wireless sensor networks and only spends moderate computation cost.In wireless networks a task often achieved by collaboration of sensor nodes. Then an attack can be implementation through the collaboration process. In order to resist these malicious attacks, the function of authentication between sensor nodes should be provided in key agreement protocol. Compared with symmetric key cryptography, asymmetric key cryptography has advantages on key management and security. So, two-party key agreement protocol based on the weil pairing protocol (A-WGKA₂) is proposed. The proposed protocol has the security properties such as forward secrecy, no unknown key-share, known session key security, no key control and no key-compromise impersonation. Further, using key tree, an authenticated group key agreement protocol based on A-WGKA₂ is proposed for wireless sensor networks. This protocol provides the node authenticate which can resist the malicious attacks.According to the features of wireless sensor networks, a security efficient group key agreement protocol based on layer-cluster group model is proposed. The network is partitioned into several appropriate cluster and then build up suitable layers to construct layer-cluster group model. On this layer-cluster group model, the subgroup keys was generated and allocated based on security elliptic curves which offered smaller system parameters, lower power consumption and faster implementations. This protocol makes full use of architecture features of wireless sensor networks, therefore it not only decreases the computational overhead and communication costs but also provide the authentication between the nodes. Similar to the above protocol a group key agreement protocol based on circular hierarchical for wireless sensor networks was proposed. In this protocol multi-linear map is employed on circular hierarchical structure to establish and allocate group key. So this protocol can not only meet security demands of wireless sensor networks but also improve executing performance.In order to provide fast authentication between two nodes in wireless sensor networks, an ID-based key predistribution (ID-AKE) scheme for wireless sensor networks is proposed. By applying the ID-based technique and the bilinear map, the proposed scheme can establish a unique pair-wise between two nodes and authenticate each other by fewer messages. In this scheme a sensor needs not to transmit its implicit certificate, so it not only provides the explicit key authenticate but also offers low communication overhead.In order to reduce energy consumption on sensor nodes, the improved ID-AKE scheme is proposed. According to the standard defines of two physical device types (a Full-Functional Device and a Reduced-Functional Device) and the experiment given by Perrig, et al which show that communication costs more energy consumption than computation, the improved ID-AKE scheme propose that the complex computational operation can be moved from sensor nodes to security management to reduce the computational overhead on sensor nodes. Furthermore, it also propose that the communication costs can be reduced by increasing certain computational overhead which can effective reduce the energy consumption on sensor nodes. Based on the above idea, the improved ID-AKE scheme uses the sensor's ID achieved the authentication between sensor nodes and security management through the process of key agreement. Furthermore, the complexity analyses show that the improved ID-AKE scheme has effective reduced the energy consumption on sensor nodes, so it very suitable for resource-constrained wireless sensor networks.