Research On Key Management Schemes For Wireless Sensor Networks Named D&H

Wireless sensor networks often suffer from various security threats, for example, nodes that exposed to unsafe environment are easy to be captured; radio signal is easy to be intercepted. So the problem of security is an important research direction in wireless sensor networks. In this thesis, the key management technology is deeply studied and a new key management scheme based on hash function and cellular model is proposed.This thesis focuses on studying and analyzing random key pre-distribution scheme and key pre-distribution scheme using deployment of knowledge. Because random key pre-distribution scheme spends less storage space in the node, has a better network scalability, supports for large-scale network, limits the influenced sphere of captured nodes, has higher network security, it is an important research direction of the current key management issues. Key pre-distribution scheme using deployment knowledge divides the deployment region and its nodes into several groupes, at the same time it divides the key pool into several groups. By this means the connectivity of the neighbor nodes can increase, thus greatly improving the security of the entire network connectivity. Due to these advantages, the key pre-distribution scheme using deployment of knowledge becomes an emerging key management technology.On the basis of the basic random key pre-distribution scheme, combining with the hash function and deployment knowledge, this thesis proposes a new scheme named D&H scheme. Firstly, on the basis of E&G scheme, combining with the hash function, this thesis proposes a new scheme named H&R scheme. In this scheme each root key becomes mid-key by hashing itself random times, and several mid-keys make up key ring that are stored in sensor nodes. When two nodes need to communicate with each other, if their key rings including keys with the same key IDs, takes the key with a larger hash depth as the shared key of the two nodes. Make all the shared keys between the two nodes and their node IDs execute XOR function, hash the result to generate communication key. The two nodes use the communication key encrypted data, secure data transmission. Execute enhanced phase after all communication keys are established, and then delete original key materials in nodes. After that the thesis analyzes the partition model, improves the regular hexagon partition model, divedes the deployment region into main area and minor area. The corresponding sub-key pool of the main area is assigned the key by the base station key pool directly, the corresponding sub-key pool of the minor area is assigned the key by the corresponding sub-key pool of the main area arrounding the minor area. This scheme can simplify the complexity of dividing sub-key pool, increase the connetivity of the adjacent deployment area. Finally, on the basis of H&R scheme, using the improved cellular model partition the deployment area and base station key pooll, this thesis proposes D&H scheme.