A novel security-oriented cooperative scheme for wireless relay networks in presence of eavesdroppers

In order to conserve energy and achieve better quality of service (QoS) provisioning, this paper proposes a novel security-oriented cooperative (NSOC) scheme for distributed wireless relay networks in presence of eavesdroppers. Our scheme includes two parts. In part one, we model the wireless relay network and analyze the secure connectivity by exploiting the secrecy graph. Then, when the result of the analysis is inferior to the security demands, our developed cooperative jamming strategy is kicked in to further assist the secure communications, which plays the important role in secure communications. In the cooperative jamming strategy, the channels established by candidate nodes are modeled as finite-state Markov channels (FSMCs) owing to the property of time-varying, and the remaining energy of nodes is considered as well. In addition, a jammer selection policy using simple priority index is depicted, taking secrecy capacity (SC) and energy balance into account. The major superiority of this scheme is to reduce unnecessary energy costs and system complexity, while assuring the security and reliability. Finally, the obtained simulation results show that our proposed scheme outperforms the existing ones especially in terms of secrecy capacity and system reward.