Physical-Layer Key Generation Based on Multipath Channel Diversity Using Dynamic Metasurface Antennas

Physical layer key generation(PKG)technology leverages the reciprocal channel randomness to generate the shared secret keys.The low secret key capacity of the existing PKG schemes is due to the reduction in degree-of-freedom from multipath fading channels to multipath combined channels.To improve the wireless key generation rate,we propose a multipath channel diversity-based PKG scheme.Assisted by dynamic metasurface antennas(DMA),a two-stage multipath channel parameter estimation algorithm is proposed to efficiently realize super-resolution multipath parameter estimation.The proposed algorithm first estimates the angle of arrival(AOA)based on the reconfigurable radiation pattern of DMA,and then utilizes the results to design the training beamforming and receive beamforming to improve the estimation accuracy of the path gain.After multipath separation and parameter estimation,multi-dimensional independent path gains are utilized for generating secret keys.Finally,we analyze the security and complexity of the proposed scheme and give an upper bound on the secret key capacity in the high signal-to-noise ratio(SNR)region.The simulation results demonstrate that the proposed scheme can greatly improve the secret key capacity compared with the existing schemes.

Introduction to Wireless Endogenous Security and Safety:Problems, Attributes, Structures and Functions

The information security and functional safety are fundamental issues of wireless communications sytems.The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the development of wireless communication security and safety technology.This paper introduces the concept of wireless endogenous security from the following four aspects.First,we sorts out the endogenous security problems faced by the current wireless communications system,and then analyzes the endogenous security and safety attributes of the wireless channel.After that,the endogenous security and safety structure of the wireless communications system is given,and finally the applications of the existing wireless communication endogenous security and safety functions are listed.

Analysis and Application of Endogenous Wireless Security Principle for Key Generation

The open and broadcast nature of wireless channels leads to the inherent security problem of information leakage in wireless communication.We can utilize endogenous security functions to resolve this problem.The fundamental solution is channel-based mechanisms,like physical layer secret keys.Unfortunately,current investigations have not fully exploited the randomness of wireless channels,making secret key rates not high.Consequently,user data can be encrypted by reducing the data rate to match the secret key rate.Based on the analysis of the endogenous wireless security principle,we proposed that the channel-based endogenous secret key rate can nearly match the maximum data rate in the fast-fading environments.After that,we validated the proposition in an instantiation system with multiple phase shift keying(MPSK)inputs from the perspectives of both theoretical analysis and simulation experiments.The results indicate that it is possible to accomplish the onetime pad without decreasing the data rate via channelbased endogenous keys.Besides,we can realize highspeed endogenously secure transmission by introducing independent channels in the domains of frequency,space,or time.The conclusions derived provide a new idea for wireless security and promote the application of the endogenous security theory.

Secret Key Generation Based on Two-Way Randomness for TDD-SISO System

A novel secret key generation(SKG)method based on two-way randomness is proposed for TDD-SISO system.The legitimate transceivers mutually transmit their own random signal via reciprocal wireless channel,then the multiplication of transmitted and received signal is used as common randomness to generate secret keys.In quasi-static channel,the theoretical SKG rates(SKGRs)of the three SKG methods,namely wireless channel based,one-way randomness and two-way randomness,are derived and compared.Further,two practical SKG schemes based on twoway randomness,Scheme-1bit and Scheme-3bit,are completely designed and simulated.Generally,Scheme-1bit applies to low signal to noise ratio(SNR)scenarios and achieves 0.13~0.86bit/T_s SKGR and 10^(-2)~10^(-5) level secret key outage probability(SKOP),while Scheme-3bit fits high SNR situation and obtains 0.93~1.35bit/T_s SKGR and 10^(-3)~10^(-4) level SKOP.At last,the national institute of standards and technology(NIST)test is conducted to evaluate the secret key randomness(SKRD)and the test results show that both of the proposed schemes have passed the test.

A physical layer secret key consistency enhancement scheme using constellation decision information

Secret key generation based on a wireless channel(WC-SKG)is a promising solution to address the security issues in wireless communication.However,the consistency of channel estimation between two legal communication nodes in WC-SKG is often poor due to the receiver noise,signal power,etc.,leading to a low secret key generation rate(SKGR).Although there are several denoising algorithms such as orthogonal transformation to address this issue,existing schemes overlook the fact that data symbols are also affected by the channel.This results in existing schemes only using the pilot symbols for channel estimation and not fully utilizing the received signal power of the WC-SKG.To address this issue,we propose a consistency enhancement algorithm based on constellation decision information(CEA-CDI),which utilizes both pilot symbols and soft decision information of data symbols to improve SKGR.Monte Carlo simulation and numerical results demonstrate that our proposed scheme can improve performance by approximately 16 dB compared to initial channel estimation.

6G无线内生安全理念与构想

6G开放融合、异构共存、智能互联的网络特点将引发更多未知复杂安全威胁,目前安全滞后于通信发展的格局必然难以应对,6G时代必须打破思维定势,催生真正具有代际效应的标志性技术.内生安全从无线网络内源性缺陷产生的共性和本源安全问题出发,通过结构导向的解决方法,具有抵御未知安全威胁的能力和通信/安全/服务内源性融合的能力.本文对6G无线网络内生安全问题、理念进行了探讨,并提出内生安全在6G超高速宽带通信、超大连接超低时延、天地一体化全域覆盖等典型场景中的应用构想,给出了若干潜在关键技术和解决方案.

Joint radio frequency front-end and digital back-end antijamming scheme based on a metasurface antenna array

An array’s degree of freedom(DoF)determines the number of jamming incidents that can be managed and the antijamming performance.Conventional arrays can improve the DoF only by increasing the number of antennas.On the other hand,when the received signal is digitized,high-power jamming will reduce the number of bits used to represent the desired signal,further increasing the difficulty of back-end antijamming based on digital signal processing.In this paper,we propose a joint radio frequency(RF)front-end and digital back-end antijamming scheme based on a metasurface antenna array.The metasurface antennas can rapidly switch patterns when receiving signals,so that a single channel can be equivalent to multiple channels and increase the DoF.We use independent component analysis to estimate the channel and then optimize the array parameters under the minimum signal-to-jamming ratio constraint of each antenna.The proposed scheme works well under high-power jamming conditions by suppressing jamming at the RF front end and using a low-precision analog-to-digital converter.Simulation results show that the proposed scheme reduces the bit error rate of the received signals by one order of magnitude compared with the conventional array.