Cryptography Feature Extraction And Analysis Of Human Physiological Parameters And Application In The Security In WBAN

Data encryption and message authentication in Wireless body network(WBAN) is a popular research in recent years. Because of its poor computing ability, limited power, short communication distance, simple topology and data sensitivity, WBAN with conventional security mechanism has not been widely used yet. However, WBAN is applied for different individuals, they have concise biological differences between each other, so that how to use the unique biological signal differences seems extraordinary meaningful to design feasible security mechanisms and protocols for WBAN.The major works in this thesis on the secure communication of WBAN are summarized as follows:1. A novel introduction to the concept of WBAN is given, followed by the definitions of the physical layer of WBAN communication and security levels proposed by the standard of IEEE 802.15.6. The current researches, the security issues, the conventional bio-encrypting methods and their limitations in implementation of WBAN are also summarized.2. The characteristics of WBAN and the network nodes are analyzed. The customary encryption and authentication algorithms are also compared. Based on the analysis, a suitable secure communication scheme for WBAN is proposed with the use of human physiological parameters.3. The available physiological parameters to WBAN are summarized, before Inter-Pulse Intervals(IPIs) is chose as an appropriate one with the model analysis. The actual circuit is designed for samples collection of IPIs, and K-S method is introduced to analysis the samples. It is firstly discovered in this thesis that IPIs is Gauss-Distribution alike.4. On the base of getting the characteristics of IPIs distribution, a new model is carried out to generate random bit data with specific method. By analyzing the cryptographic properties, experiment results that the number of ‘0’ is very equal to that of ‘1’ and the average of linear complexity is around the half the sequence length is carried out. Besides, the maximum hamming distances of same person, same time, different part of body is less than 10, and the most hamming distance of different person, same time, same part of body is between 40 and 85.Above all, the random bit sequence generated by IPIs is proven to have a good randomness and consistency on the same time, on the different part of the same people, which means it is suitable as the encryption key of WBAN.