Research On Physical Layer Key Generation Mechanism Of Cognitive Radio Networks

Cognitive radio networks(CRNs)is one of the best solutions to solve the contradiction between the supply and demand of spectrum resources.The secure communication between users is the premise of the normal operation of CRNs.Extracting and establishing a secure and effective shared key is the fundamental countermeasure for securing the communications among users.In this paper,the physical layer wireless channel characteristics are used to study the generation of shared keys between users.The main research contents are as follows:Research on key generation mechanism based on adaptive multi-bit correlation quantization: Existing key generation schemes suffer from the high bit disagreement rate and low bit generation rate.We propose an adaptive multi-bit correlation quantization scheme.In order to reduce the bit disagreement rate,we discard the measurements which are abnormal or located near the interval boundary.In addition,we also set a paired value for each measurement,so that the generated key is related to multiple measurements to ensure the randomness of the final key generation.Several experiments are implemented to verify the effectiveness of the proposed scheme.The results show that our scheme has advantages in bit disagreement rate and bit generation rate.Research on symmetric channel key generation mechanism based on channel characteristics: In order to further optimize the bit generation rate and bit disagreement rate,we propose a modified channel quantization with single guard-band to quantify the extracted channel measurements.Furthermore,we implement a key extractor to further increase key generation rate and ensure randomness of generated key.The experimental results show that compared with other related schemes,our scheme has significantly improved the bit generation rate and the bit disagreement rate.Group secret key generation and analysis based on central node: In centralized cooperative sensing,the fusion center uses the symmetric channel key generation mechanism based on the channel characteristics to generate local pair keys with other secondary users in the group.The numerical analysis shows that the proposed group key extraction scheme can achieve group key generation rate under different conditions.The results show that the group secret key rate increase with the increase of the signal-to-noise ratio(SNR)and does not change with the increase of nodes in the group.The proposed scheme outperforms contemporary ones with higher group secret key rate.