Research On Performance Analysis Of Wireless Communication Security Based On Key Extraction

Based on heterogeneous network architecture and new wireless technologies,the fifth generation(5G)mobile communication provides support for massive device access,multiple wireless services,and exponentially increasing data traffic.Due to the openness of wireless channel and significant improvement of terminal computing capacity,5G requires a higher communication security guarantee.Physical layer security has become a research hotspot in recent years,providing possibilities for the absolute security of 5G communication.Key extraction mechanism of 5G physical layer utilizes the random characteristics of the wireless channel to generate the communication key to encrypt and protect the information.This thesis focuses on the security performance of physical layer key extraction mechanism security,and the main contributions are summarized as follows:To cope with the lack of security evaluation algorithm of the 5G physical layer key extraction mechanism,two security evaluation algorithms are proposed which named as optimal method and suboptimal method.The channel is modeled using the wiretap model and the Hidden Markov Model(HMM).The security level of the key extraction mechanism can be represented by a specific numerical value.The optimal method has a superior performance but exponential level complexity.For reducing calculate complexity,suboptimal method with multiple adversaries algorithm is proposed,sacrificing performance for calculating complexity reduction.The performance of the two proposed algorithms are compared by simulation.To verify the universality of the two security evaluation algorithms proposed in this thesis,we choose the typical 5G application scenario Vehicular Ad-Hoc Network(VANET)as a practical application scenario.In VANET,a key negotiation mechanism is proposed which can hide the identity of the communicator.This key negotiation mechanism is based on the traditional public key cryptosystem and uses digital signature to protect key correctness.The proposed two security evaluation algorithms can evaluate the security level of the key negotiation mechanism.The security performance and less time overhead of this key negotiation mechanism are verified by simulation.To overcome the shortcomings of existing group key management schemes in security performance and communication resource overhead,a group key management mechanism based on two-leader strategy is proposed.This group key management mechanism is based on the key negotiation mechanism which can hide the identity of the communicator proposed in this thesis.The two-leader strategy is adopted for identity registration and key negotiation.The threshold secret sharing scheme is used for key distribution,identity authentication and key recovery of new joining node.The proposed two security evaluation algorithms can evaluate the security level of this group key management mechanism.The security performance and low time overhead of this group key management mechanism are verified by simulation.