In Vivo Fingerprint Research

The establishment of Maxwell's equations marks the progress of electromagnetic research from naive observation and description to scientific theorization.According to the predecessors of wireless body area networks(WBAN)electromagnetic research,it is known that body-centric communication is a communication paradigm for the 5G and post-5G eras,and its next development focus is to explore millimeter wave channel model.According to the digital human body model,the WBAN channel is highly correlated with the subjects,and has good test specificity and inter-subject heterogeneity.Through the WBAN channel analysis model,it is confirmed from the physical level that surface waves and creeping waves are the main factors causing the above differences.The combination of millimeter wave bands and WBAN can bring significant advantages such as miniaturization of electromagnetic devices,improved communication bandwidth,enhanced channel robustness and perceptibility.As the first communication paradigm to embed humans into the network structure,WBAN relies on body-centric communication equipment to build a form of data connectivity around the human body with the user as the core of the network,opening up the natural isolation between traditional communication networks and users.The design idea of the user itself being both the data source and the sink,further consolidates the overall process of wireless communication and realizes the seamless transfer of user data flow.WBAN's body-centric attributes make it inevitably carry user's private data,so it requires reliable security measures,but the current IEEE 802.15.6 international standard has serious security risks in terms of authentication,authorization,and privacy.Security experts believe that traditional biometric authentication gives priority to ease of use while leaving an attack backdoor.There is an urgent need to find new ways for identity authentication,especially in private networks full of user physiological privacy data.Physical layer security has become a new security choice for emerging wireless network architectures due to its clear logic,fewer resource requirements,and security that can be verified through information theory.Based on the instructor's existing biometrics research background,combined with the accumulation of body domain channel modeling research in our group,degree applicants have refined the Patterns-of-Life authentication into bornprints research,and done the following research within this framework:1.According to the typical research method of WBAN,based on the full-body electromagnetic model,quantify the electromagnetic characteristics of the hand palm,which interacts closely with devices.In the 27-28 GHz,29-30 GHz and 31-32 GHz millimeter wave bands,the local channels of the palm were measured.In a single frequency band,the net body loss of different subjects varies about 3 d B,and the channel characteristics are closely related to hand size and dielectric parameters.2.A new keyless authentication method using wireless channel characteristics is proposed.Use subject-specific hand local channel transmission coefficients(S21)as bornprints recognition.Through the data collected through the prototype system,which confirmed the availability of the method.3.A body centric signature authorization method based on the time-frequency domain characteristics of multi-band signals is proposed.Using the inherent identity-related time-frequency domain information generated by the superficial creeping wave and the spatial surface wave of signer's hand,the natural signature accompanying the communication process is realized.This method can meet the necessary conditions of information theory noise channel model signature.4.Propose a weak random source of body centric channel,which realized by microwave system.This method combines users and WBAN equipment without adding additional hardware.By quantifying the body centric channel,an energy-friendly random source with good high-frequency random performance is obtained.It can be used as an optional solution for random amplification.5.Through the behavior mode assisted authentication perspective,the body centric channel bornprint realizes contactless gesture recognition.Reduce direct contact in the medical process to quickly and effectively eliminate iatrogenic infections.The original S-parameters can achieve 82%(27 GHz)and 89%(37 GHz)basic recognition accuracy through simple statistical analysis.This dissertation can be regarded as the pillar and beam work of bornprint research,transforming the radio wave carrier of information into an excellent ubiquitous sensing medium.The antenna and propagation with a good theoretical basis promote the scientific theorization of wireless networks(especially WBAN)security.