Key Generation Scheme Based On Wireless Channel Characteristics And Biometrics In Body Area Network

The traditional medical monitoring system requires patients to be hospitalized to detect various physiological indicators,so it cannot cope with sudden illness.With the development of wireless body area networks,wearable sensor nodes and terminal devices have become popular and become a new type of medical monitoring methods.Due to the low energy consumption limitations of sensor nodes in wireless body area networks,complex calculation and key distribution processes should be avoided as much as possible under the premise of ensuring the safety of physiological data.Based on biological characteristics and wireless channel characteristics,this thesis aims to improve the efficiency of “plug and play” of sensor nodes in body area networks,reduce sensor energy consumption,and protect the safety of user's physiological data.Two different key generation schemes are proposed:1)Fusion key generation mechanism based on ECG(Electrocardiogram)and RSSI(Received Signal Strength Indication)in body area network.Based on the similarity of biological signals on the same human body and the reciprocity of RSSI,the ERKA scheme is proposed.The ERKA scheme does not need to perform complicated calculations,and at the same time can ensure the safety of real biological characteristics.ERKA is mainly divided into two steps: the first step is to use the XOR operation to merge ECG features and RSSI features;the second step is to use the fusion features to encrypt the symmetric key and use Fuzzy Vault to distribute the symmetric key.The proposed fusion feature is mainly based on two considerations: The first point is to protect the privacy of the biological feature.The fused feature hides the true biological feature.Even if the attacker obtains the fusion feature,he cannot know the true biological feature.The second point is that it can effectively resist multiple template attacks.Due to the channel fading characteristics,the RSSIs between nodes are different,so even if each template has the same physiological characteristics,it will not have the same fusion characteristics.2)Symmetric key generation scheme based on group and wireless channel in wireless body area network.This solution can achieve device authentication and key generation only by measuring the RSSI value of the wireless channel.This method has low requirements for the wireless body area network,does not require additional hardware support,and avoids a complicated key distribution process.This scheme mainly has two stages of identity authentication and key enhancement.In the identity authentication phase,each node is classified by calculating the average change value of RSSI.The smaller the change value,the higher the degree of trust.Then each node establishes a trust table through multi-hop authentication to complete the identity authentication of the sensor nodes on the same human body.In the key enhancement phase,nodes establish multi-hop communication through virtual groups,use ASBG(Adaptive Secret Bit Generation)technology to extract RSSI key bits,and pass the key through XOR operation to achieve the purpose of key enhancement.