This paper proposes a social-aware cooperative interference strategy for physical layer security, which not only considers the physical characteristics of the devices, but also considers the social relationship among users, and combines the two to increase the confidentiality capacity of the communication network. This paper studies the security issue of a multi-user communication network in the existence of eavesdropper and the source node with the help of cooperative interference node. To be specific, we define a trust value for each node to indicate the social relations and network interactivity between nodes. This paper proposes a two-layer network cooperative interference system model, by constructing the utility function of the main channel and the utility function of the eavesdropping channel, and the goal of maximizing the utility function of the entire network is proposed. The problem can be described as a one-to-one matching game, and the simulation results display that this scheme can obtain a higher confidentiality rate compared with the existing scheme.
This paper proposes a social-aware cooperative interference strategy for physical layer security, which not only considers the physical characteristics of the devices, but also considers the social relationship among users, and combines the two to increase the confidentiality capacity of the communication network. This paper studies the security issue of a multi-user communication network in the existence of eavesdropper and the source node with the help of cooperative interference node. To be specific, we define a trust value for each node to indicate the social relations and network interactivity between nodes. This paper proposes a two-layer network cooperative interference system model, by constructing the utility function of the main channel and the utility function of the eavesdropping channel, and the goal of maximizing the utility function of the entire network is proposed. The problem can be described as a one-to-one matching game, and the simulation results display that this scheme can obtain a higher confidentiality rate compared with the existing scheme.
Cooperative jamming is a popular technique for physical layer security, which is helpful to increase the secrecy of communication networks. To enhance the performance of cooperative jamming, this paper proposed a two-layer network consisting of a social network and a physical communication network. Each user is in the social network and their willingness of providing jamming is modeled by a susceptible-infective-recovery(SIR) spreading model, while devices of each user and their connection are presented in the physical communication network as the lower layer. The concept of social tie is introduced to the description of connections between two layers, and game theory is used to model processes of cooperative jamming. It is discovered that stronger social tie and SIR model is helpful to decrease secrecy outage probability of communication networks. Furthermore, our proposed two-layer network can raise the efficiency of designing strategies for cooperative jamming. Simulation results also demonstrate the proposed model and algorithms successfully enhance the secrecy performance for communication networks.
In wireless network, when using classical game theory to study physical layer security, the energy-limited transmission nodes tend to choose non-cooperative strategy in order to maximize their own secrecy rate, resulting in reduced network secrecy rate.To solve this problem, the paper proposes a cooperative interference method for physical layer security based on evolutionary game.First, it defines the strategies (sending artificial noise or signal) and benefits (secrecy rate under different strategy combination) according to the evolutionary game.Then, the transmission nodes adjust strategy to maximize benefits based on current network state and difference between cooperation benefit and average expected benefit; Finally, the conditions that the transmitting nodes can cooperate with each other could achieve, and the network is evolution from an unstable state to a stable cooperative state to improve the secrecy rate of the system.Simulation and analysis results show that under the Gaussian channel, compared to the traditional game method, the network secrecy rate of the proposed method can be improved 1bit/s/Hz.
With the advent of mobile telephony, complemented by the availability of economic infrastructure devices has provided users the freedom to communicate and perform everyday tasks wirelessly. The access to information anywhere anytime provide users more flexibility to communicate, nonetheless it also makes communication more vulnerable to eavesdropping. Security is now considered as an important issue in the design of modern wireless communication system. In contrast to the conventional systems where security issues are dealt in the upper\nlayers of the protocol stack, in this thesis we focus our attention to construct security schemes by exploiting the attributes of the physical layer. \nIn the first part of the thesis, we consider a two-user multiacces channel where the two encoders, Encoder 1 and Encoder 2, are allowed to communicate with each other over a unidirectional noiseless bit-pipe of finite capacity in the presence of an adversary. In this model, the role of Encoder 2 is restricted to only help Encoder 1 in securing information from adversary. For this model, we\nestablish fundamental performance limits on secure communication and characterizes the secrecy capacity in some extreme cases of cooperation between the encoders. The second part of the thesis considers an elementary\nnetwork, which consists of four nodes – a source, a relay, a legitimate receiver and a passive eavesdropper. In this network, the link between two nodes consists of multiple parallel channels as subchannel. Towards this end, we establish bounds on secure communication. We show that for the case in which the relay does not listens to the source, under certain conditions secrecy capacity is established. In the last part of the thesis, we studied a two-user multi-input multioutput X-channel with local feedback and delayed channel state information\navailable at the transmitter in high signal-to-noise ratio regimes. In this setting each transmitter transmits independent messages to both receivers that need to be kept secret from each other. We characterize the optimal sum secure degrees of freedom region of this model.
The existing physical layer security algorithm could guarantee secure communication to a certain extent. However, eavesdropper can get more information from legitimate receivers whose channel condition is worse than other users. In order to improve the system's security, a novel physical layer security algorithm based on cooperative jamming for multiuser MIMO system is proposed in this paper. Firstly, a multi-user MIMO system of security is established, combining transmit beamforming and artificial noise. Then, the status of each user's characteristics is described respectively. And users are divided into a secure communications group and interference group for scheduling according to the characteristics of the user's state. Further, interference group assists the base station interference eavesdropper by adjusting the beamforming weights. Simulation results show that the proposed algorithm can increase the secrecy capacity by 2.4bit/s/HZ averagely, which can improve security for multi-user MIMO system.
Security functionality handled by higher layers of OSI model is a costly affair due to key management and complex mathematical encryption-decryption mechanisms in the scalable networks like wireless sensor networks (WSNs). WSN consists of resource constrained tiny sensor nodes for which battery is their lifetime. Physical layer security is the cost effective solution for such adhoc networks. The cooperative diversity mechanism makes use of the benefits of wireless sensor network scalability in terms of cooperative resource sharing in which multiple diversity channels are created which results into improved wireless connectivity. Cooperative jamming principle is used where the source transmits the encoded signal and at the same time relay transmits the weighted jamming signal to increase the equivocation of the eavesdropper. This work proposes a novel cooperative jamming mechanism for scalable networks like Wireless Sensor Networks (WSNs) which makes use of friendly interference to confuse the eavesdropper and increase its uncertainty about the source message. Channel fading is exploited to achieve perfect secrecy. The full communication link is built with the help of Information theoretic source and channel coding mechanisms. The whole idea is to make use of normally inactive relay nodes in the selective Decode and Forward cooperative communication and make them work as cooperative jamming sources to increase the equivocation of the eavesdropper. In this work, eavesdropper’s channel’s equivocation is compared with the main channel in terms of mutual information and secrecy capacity.
The physical layer security technology is a technical scheme developed in recent years to solve the problem of information security transmission in wireless communication networks. As one of the physical layer security technologies, cooperative jamming often requires collaborative nodes to actively cooperate with other nodes with secure communication requirements to transmit information. In the environment of heterogeneous wireless network, each wireless node is relatively independent, the relationship is both cooperative and competitive, and the nodes are selfish. In this paper, we study the information transmission between the source and destination nodes, and form a virtual beamforming through the cooperation of the jamming nodes to point to the malicious wiretap nodes, so as to achieve the physical layer secure communication. First, the interest distribution relationship between the source node and other cooperative interference nodes is modeled as the Stackelberg game. The source node pays the consumption of the power consumed by the cooperative jamming nodes and motivates the cooperative interference nodes to participate actively. Then, the competition relationship among all the cooperative nodes is built as a non-cooperative game, so as to promote the reasonable pricing of the consumed power when each node participates in collaboration. When the security rate between the source node and destination node is constant, the power allocation of source and cooperative nodes and the equilibrium point of power price exist and are unique. Through the combined optimization of the two games, the power pricing and power allocation can be dynamically optimized according to the change of the network environment. The simulation results show that the power dynamic allocation and power dynamic pricing have good convergence, and the source node provides a train of thought for the selection of cooperative nodes and their number.