Study On Authenticated And Key Exchange Protocols In Wireless Body Area Network

Wireless sensor network has gained rapid development in recent years, it plays an important role in the fields of military, commercial, medical and other aspects. At the same time, wireless body area network(WBAN), which is the branch of wireless sensor network in the field of medical care, emerges at the right moment. Wireless body area network is a kind of network placed in human body, and consists of several minitype sensor nodes and a control node. Wireless body area network belongs to the category of wireless network, there are much potential security risk in wireless network on account of the characteristics of movement、openness and the dynamic topology of it. It is vulnerable to illegal attack in the process of information interaction in the network; hence it is necessary to use relevant cryptology to guarantee the security of communication.The security protocol is message exchange protocol based on cryptology, and aimed at providing kinds of secure services in network environment. Security protocol include authentication key exchange protocol and so on, is an important component and theory guarantee of network security. Study on authentication key exchange protocol is always the research hotspot in the field of network security. We designed three new-style authentication and key exchange protocols suitable for WBAN according to its characteristics, worked out the analysis result by formalization and the nonformalization method respectively, and give the outcome of simulation test under software environment. The major contributions are outlined as follows.1. Designed the layered network model according to the network topology structure defined in IEEE 802.15.6 standards, and proposed three kinds of authentication and key exchange protocols suitable for WBAN. In the protocols each normal node pre-shared a pair of secret key with control node. The three protocols adopted different authentication method: Protocol I is initiated by the second-level node authentication and generates the session key while the control node select the proper first-level node to link; Protocol II should be performed by the nodes in coordination mode. The first-level node launches authentication process by broadcasting and generates a pairs of session key; In Protocol III, the authentication process is launched by the second-level node and generates a pairs of session key. The primary node acts as a relay node and does not decrypt the messages, while just forwards the information to second-level node. The protocols provides certification selectively under different scenarios of WBAN, at the same time a pair of the session key is generated between different level nodes efficiently and succinctly.2. There are two kinds of methods to analyze security protocols: formalization and the non-formalization method. In fact, many security protocols still have loopholes even get through formalization analysis, some security flaws are found years later. Yet non-formalization method can test the security of protocols effectively. This thesis introduces the typical formalization and the non-formalization analysis methods, emphasis on BAN logic of the formalization way, and the three authentication key exchange protocols are analyzed and proved with it respectively. The initialization conditions, certification rules and reasoning rules of BAN logic are given, with these we deduce the ultimate belief of the protocols, results show that the proposed protocols are secure and effective, conform to the security requirements of the wireless body area network.3. The running time simulation test of the protocols is given. Main text introduces the encryption process of the symmetric encryption standard AES and the results of time test of authentication and key exchange protocols in wireless body area network are given based on AES. Here we completed the emulation in C language, and test the running time of each protocol in VS2010.The results show that the proposed protocols have good efficiency and practical application prospect.