The Research On Key Technologies Of Key Generation And Security Enhancement Based On Wireless Channel Characteristics

The wireless network has the advantages of not being restricted by geographical location,covering a wide range,easy to deploy and so on,and it is widely used in various fields.At the same time,the open nature of the wireless network also makes it face serious security problems,such as eavesdropping,interference,counterfeiting and tampering.Attackers use various means to disrupt communication and seriously threaten the security of the network.The physical layer security scheme based on the characteristics of wireless channels provides a new solution to the security of wireless communications.The randomness,spatial temporal un-correlation,reciprocity and unpredictability of wireless channel decide that it can be used as a random signal source to extract key,and also can be used for identity authentication,anti-jamming attack and so on,to achieve security enhancement.Based on the study of information security theory and the research status at home and abroad,this paper studies the related technologies of extracting key and security enhancement by using wireless channel characteristics.The main research work is as follows:(1)Research on the quantization algorithm in the process of secret key generation based on wireless channel characteristics,summarizes and analyzes the advantages and disadvantages of existing quantization algorithms.Aiming at the problem that the Quantization with Guard-band(CQG)algorithm removes more eigenvalues and leads to a lower key generation rate,an improved algorithm based on CQG algorithm is proposed.The difference between the improved algorithm and the CQG algorithm is that the CQG algorithm deletes all the eigenvalues in the guard interval,while the improved algorithm keeps the eigenvalues which will be quantified as the same ones in the guard intervals according to the location index information exchanged by the two parties.The improved algorithm improves the key generation rate by reducing the deleted eigenvalues.(2)Put forward the idea of comprehensive analysis of quantization and information reconciliation.Quantization and subsequent information reconciliation are closely related during the key extraction process,but the existing key generation scheme separates the two phases and does not analyze the overall performance.This paper combines the improved quantization algorithm with information reconciliation to verify the overall performance through experimental simulation.The experimental results show that the total key generation rate of the improved algorithm is significantly improved when the key mismatch rate decreases to zero after combining two stages.And the generated key can pass the NIST randomness test to meet the security requirements.(3)In order to resist jamming attacks in wireless networks,a channel hopping scheme basedon wireless channel characteristics is proposed.a random channel hopping sequences for controlling channel hopping can be generated by using wireless channel as a random signal source.Experiments are designed in the real-world environment to verify the performance of the solution in terms of channel agreement rate,distribution of channel selection,and security.The experimental results show that channel agreement rate can reach more than 95% with almost equally channel distribution when the initial key rate is less than 4%,and the security can be guaranteed.