Research On Technologies Of Security Key Management In Wireless Sensor Networks

Wireless sensor network (WSN) is a next generation of network which integrates the technologies of sensor, micro-electro-mechanism system, wireless communication and distributed computing. Its applications have extended over environment monitoring, traffic management, heath and medical community and so on. Security about wireless sensor network is a very challenging at integrated effect of many factors, such as intricate secure environment, various secure requirement and limited resources. As a fundamental requirement for providing security in wireless sensor network, key management plays an essential role in authentication and encryption. In this paper, we focus on the key issues of key management to design secure and efficient key management schemes for wireless sensor network. The main contributions are outlined as follows:? A mutual broadcast authentication protocol for wireless sensor networks based on Fourier Series is proposed according to the problems that the main broadcasting authentication protocol for ?TESLA is limited in authentication delay, more initial parameters, time limit, large key chain and easy to cause network congestion. It is achieved for broadcast authentication that according to the characteristic of continuous-integrability function f(x) in [-?,?] which could be expanded into Fourier Series, and achieving a mutual broadcasting authentication between base station to node based on the characteristic of quadratic form function f(x). The analysis result of safety performance show that a single node in the network is captured will not affect the security of broadcasting authentication protocol, low-overhead for computation and communication, the base station can conduct random broadcasting, and nodes can be instant authentication for broadcasting messages received.? A key management scheme based on quadratic form polynomial for wireless sensor network (WSN) is proposed for the problems that some existing key pre-distribution schemes are limited in key sharing and network connectivity probability between neighbor nodes. It beyonds the current ideas for establishing shared key based on quadratic symmetric polynomial and presents the multiple asymmetric quadratic form polynomial, and analyzes the orthogonal diagonalization properties of quadratic form to generate the key information by the relationship between eigenvalues and eigenvectors of the quadratic form, the nodes could achieve identification and generate the unique session keys between the neighbor nodes through exchanging the key information. Compared to some key existing pre-distribution schemes, the analysis of performance show that this scheme could resist captive, have good scalability and connectivity, and have a lower storage cost, a lower communication overhead. Moreover, it creates a new direction for studying on key pre-distribution management schemes based on multivariate polynomial.?A group key management scheme for wireless sensor networks based on chinese remainder theorem is proposed according to LKH, EBS and other group key schemes limited by the network structure, collusion attack, computational complexity, high energy consumption, and the single point of failure. That chinese remainder theorem can tends to be lagrange interpolation polynomial based on the function property of chinese remainder theorem. Based on this characteristic, the base station generates a Lagrange interpolation polynomial function f(x), and can tend to be mix-function f(x)-f(x)Ki by f(m(i))=1, m(i) is the node key information. Then, node can obtain the group key Kj by will receive the message f(m(i))-Kj. The analysis results of safety performance show that the protocol has good network security, scalability, anti-capture, low computation.? Based on the before contents of chapter 3 to chapter 5, a key management scheme based on improved localized encryption and authentication protocol (ILEAP) is proposed reference on the structure of LEAP which supports four types of keys, it supports five types of keys:broadcast authentication key, individual key, session key, group key and cluster key. And, it presents five new key generation methods for each key based on the defects of LEAP protocol which is too dependent on the primary key generation, broadcasting authentication key based on Fourier series, session key based on quadratic form polynomial, individual key, group key and cluster key all based on chinese remainder theorem special characteristic in Lagrange interpolation polynomial. Security analysis results show that the new improved protocol ILEAP is more secure and applicable.