Study On Physical Layer Security Mechanisms Based On Wireless Signal Processing

In the research of wireless communication technology,the security issues are always emphasis and difficulty.Because of the broadcast nature of wire-less communications,the communication users lack physical boundaries,which make the wireless signal easily be eavesdropped and tampered by illegal users.Due to these attacks mainly exist at the "signal level",the traditional security mechanisms have insufficient in defending against them.Compared with the traditional security mechanisms,the physical layer security mechanisms have two advantages:First,the physical layer security mechanisms can address com-munication security at the "signal level",which are effective complement of the traditional security mechanisms.Second,compared with the traditional secu-rity mechanisms,the physical layer security mechanisms need less costs,which is suitable for the low power wireless networks.All in all,the study on physical layer security mechanisms has important meanings.From the view of wireless signal processing,this thesis starts the research at the "signal level",including the physical layer security transmission,the physical layer security access and the physical layer reliable transmission.The aims at designing the physical layer security mechanisms with an end-to-end approach to improve the security of the whole communication process.The main contents and contributions can be summarized as follows:1.Physical layer key generation schemeThe key encryption can ensure the confidentiality and the integrity of the transmitted information.According to the negotiation issue of the physical layer key generation,we propose the fuzzy key generation scheme based on physi-cal layer fingerprints.Specifically,we design the fuzzy key extractor and pro-pose the negotiation schemes with respect to the eavesdropping attack and the tampering attack.The security and feasibility are analysed both in theory and simulations.2.Physical layer authentication schemeThe physical layer security access via physical layer authentication can defend against the physical layer spoofing attack and the man-in-the-middle attack.The scheme mainly includes two parts:The first part is the physical layer authentication in wireless sensor net-works,which focuses on the authentication under the threat of an intelligent location spoofing attack.First,an intelligent location spoofing attack is pro-posed,the feasibility of it is analyzed and the optimal location spoofing attack is derived.Then,according to the attack,the physical layer cooperative au-thentication scheme is designed,and the related performance analysis is given.Considering the computational complexity of the scheme,an acceleration algo-rithm is proposed.Finally,the performance of the proposed scheme is analyzed with the state-of-the-art schemes via simulations.The second part is the physical layer authentication scheme in mobile cog-nitive radio networks,which can authenticate the primary user in the presence of the primary user emulate attack.According to the change of network topology and dynamic communication environment,we propose a robust primary user distributed authentication scheme,and analyze the performance of the proposed scheme by theory and simulations.3.Physical layer anti-intelligent jamming schemeThe physical layer anti-intelligent jamming can improve the signal to inter-ference plus noise ratio,which can realize the physical layer reliable transmis-sion.The deep reinforcement learning based anti-intelligent jamming scheme is studied.Considering an intelligent unmanned aerial vehicle jamming attack,a dynamic game is modeled,and the optimal anti-intelligent jamming strategy is derived.As per the proposed strategy,the existence of Nash equilibrium is proved,and the computational complexity of the scheme is analyzed.Finally,the performance of the proposed strategy is analyzed by simulations.