Partner selection and incentive mechanism for physical layer security

We study user cooperation to enhance the physical layer security. Specifically, the source cooperates with friendly intermediate nodes to transmit message securely in the presence of multiple eavesdroppers. We propose a cooperative framework, whereby the source selects multiple partners and stimulates them by granting an amount of reward. First, multiple cooperative relays and jammers are selected by the source using greedy or cross-entropy based approaches. Then, the source and the partners negotiate for the payment and transmission power, which is modeled as a two-layer game. At the top layer, a buyer-seller game is utilized, where the source buys the service provided by the partners. At the bottom layer, all the partners share the reward by determining their transmission powers in a distributed way, which is formulated as a non-cooperative power selection game. By analyzing the game, the partners can determine the transmission powers for cooperation, while the source can select the best payment. To further improve the utility of the source, a set of reward allocation coefficients are introduced and optimized using particle swarm optimization approach. Simulation results are provided to demonstrate the performance of the proposed schemes.