Evolutionary game based dynamics of trust decision in WSNs

Trust decision made by sensor nodes and its dynamics constitute building blocks to secure and stabilize the whole Wireless Sensor Networks (WSNs). To disclose this evolutionary process, we study the dynamics of a sensor node making a trust decision that will determine whether to cooperate with others. A trust game for sensor nodes is created to reflect sensor nodes´ utilities during their trust decisions. With evolutionary game theory, we illustrate the replicator dynamics of trust evolving of sensor nodes. Under different parameter values we prove theorems in which evolutionarily stable strategies can be achieved. These theorems provide a theoretical foundation to design a trust management system in WSNs, and supply the conditions that will make sensor nodes select optimal strategies as their final stable states. Experiments have verified the results attained from the proposed theorems.