Physical Layer Information Security Based On Wireless Channel Characteristics And Cooperative Communication

The broadcast characteristics of wireless communication network make its transmission information security face greater challenges.The traditional secure communication mechanism based on modern cryptography theory relies on the encryption and encapsulation of transmission information,which is difficult to meet the requirements of high-security and low-complexity encryption algorithm for wireless communication nodes with limited energy and computing capacity in dynamic wireless networks.Physical layer security is different from the traditional encryption communication mechanism,which uses the physical characteristics of wireless channel to provide security for information transmission.It is considered to be an information security solution with broad application prospects in the field of wireless communication.Physical layer security mainly includes physical layer security capacity analysis and physical layer key generation technology.This paper makes an in-depth study of these two branches.Aiming at the influence of the selfishness of wireless nodes on the security rate of wireless signal transmission in heterogeneous wireless network environment,the communication information transmission between source and destination nodes is studied.Through Cooperative relay of cooperative relay nodes,virtual beamforming is used to point to destination nodes to achieve the physical layer security communication.First,the power distribution relationship between the source nodes and the cooperative relay nodes is modeled as a Stackelberg game.The source node pays for the power consumed by the cooperative nodes to encourage the relay node for encouraging the relay node to active participation in the cooperation.Then the competition relationship between the participating cooperative nodes is constructed as a non-cooperative game so as to promote the dynamic pricing of the power consumed by each node during the cooperation.In the case of ensuring a certain communication security rate between the source node and the target node,through the above game model can realize the power allocation of the source node and the cooperative relay node,as well as the existence and uniqueness of the equilibrium point of the power price.The simulation results show that the power dynamic allocation of the source node and the power dynamic pricing of the relay nodes have good convergence.Aiming at the poor adaptability of the physical layer secret key generation schemes based on the amplitude characteristics of the wireless channel,a method for generating the secret key by the equal probability quantizing of wireless channel amplitude characteristics is proposed.This method is based on the wireless eavesdropping channel system model,through the mutual transmission of channel detection signals between the legal parties,the characteristics of the wireless channel are analyzed,and the channel amplitude characteristics are extracted.Based on this characteristic,an equal probability quantization method is used to generate secret key random parameters to improve the adaptability of the quantization threshold in a dynamic communication environment.Experimental results show that,compared with the equal interval quantizing,this scheme can guarantee the randomness of the generated secret key random parameters,and can effectively improve the consistency and security of channel characteristic quantization the secret key random parameters generated by this scheme have good consistency and security.In the communication environment with little change of channel characteristics,Equal probability quantization the secret key generation scheme for wireless channel amplitude characteristics has the problem of low rate of generating key random parameters.Aiming at this problem,the secret key extraction method based on joint characteristics of amplitude and phase of wireless channel is further studied,and its performance is tested.The experimental results show that the scheme can significantly improve the generation rate of the random parameters,and the matching rate of the random parameters between the legal parties is kept above 0.88,while the bit error rate of the key random parameter between eavesdropper and the legal party is close to 0.5.In addition,the key is generated based on the joint characteristics of amplitude and phase of wireless channel is used to encrypt the transmission information,and the security of the transmission information is tested and analyzed.The test results show that using the key to encrypt the transmission information can improve the security of the transmission information.Physical layer key generation technology provides a feasible idea to realize the ideal secure communication by using the uniqueness and reciprocity of wireless channel,but the current physical layer key generation technology is difficult to meet the key update rate of one-time pad.In order to solve this problem,we can use the absolute security of the physical layer security capacity analyzes to assist transmission of random keys,so as to make up for the defect of low key update rate in the physical layer key generation technology.