Research On Key Generation And Negotiation Technology Of Wireless Channel Physical Layer

After entering the 21 st Century,the general public can get rid of the fetters of wire communication and communicate with each other easily and conveniently at any time benefited from the rapid development of wireless communication technology.Therefore,wireless communication has become the mainstream communication way in social production and life.However,due to the broadcast and openness of wireless communication,communications are easily accessed by eavesdropping,which create a great challenge to the privacy and security of wireless communication,and even affects personal life and social stability.How to protect the security of information effectively in wireless communication has become the focus of technology research.Wireless channel physical layer key technology is a new technology to enhance wireless communication security,in the communication mode of Time Division Duplexing,it utilizes the reciprocity and time-varying on both sides of the wireless channel,not only extract the same channel feature information to generate key,but also realize the dynamic key generation,combine with traditional communication security technology to improve the security of existing wireless communication.However,due to the effect of channel delay and environmental noise,the initial key will have low coherence rate under the condition of poor communication generated by sending and receiving ends.It needs to be solved through the Key Negotiation when the key error caused by the incomplete identical channel characteristics in the key generation process.Key Negotiation is composed of two parts: Key Information Harmonization and Key Enhancement.Key Information Harmonization is responsible for correcting the wrong code and improving the coherence rate;The Key Enhancement is responsible for determine whether the Key Information Harmonization is successful or not,and to delete the key which failed to Negotiation.In this paper,we extract the channel characteristics of the wireless channel to generate the secret key and enhance the utility of the key through Key Negotiation,simulate the accuracy and speed of the Key Negotiation in the end.The main research work is as follows:(1)To review and research the Key Information Harmonization methods of wireless channel physical layer,and to sum up their advantages and disadvantages.A method of key information harmonization based on improved LDPC calibration is designed,this method uses the offset-base calculation formula to update the calibration node,make LDPC can correct the original key of the inconsistent physical layer.This paper simulates the error correction performance and the iteration number of the algorithm.(2)Using Hash Function code encoding algorithm to enhance the key after the Key Information Harmonization,determine the consistency of the key and remove inconsistent key.On the basis of the standard Key Enhancement scheme,a simplified Key Enhancement scheme is presented.The accuracy of two Key Enhancements was simulated,compare their performance.(3)The multi-bit quantization wireless channel physical layer key.is studied.By dividing the feature space,multi-bit physical layer key generate scheme based on three features information extraction of amplitude,phase and amplitude phase combination is obtained,their error rate and randomness are compared through data simulation.To design the information reconciliation scheme suitable for multi-bit quantization physical layer key based on the improved modification of LDPC.Finally,the error correction performance and iteration number of the algorithm are simulated.