Online Scheduling for Multi-Hops Wireless Networks With Security Constraints

We consider wireless multi-hops networks in which each node desires to securely transmit the message. To guarantee secure transmission, we employ an independent randomization encoding strategy to encode the confidential message. We formulate the problem as network utility maximization. Based on the secure communication strategy, we first propose a simple and provable dynamic control algorithm for the case that the length of secrecy codewords is infinite. The control algorithm not only satisfies end-to-end perfect secrecy constraint, but also keeps the network stability. Next, we further consider the case that a finite length of secrecy codewords is performed, in which the possibility of perfect secrecy is eliminated. For this case, we develop an improved control algorithm, subject to network stability and secrecy outage requirement. On the basis of the Lyapunov optimization method, we obtain the optimal algorithm, which is decomposed into end-to-end secrecy encoding, flow control, and routing schedule. The simulation results show that both of the proposed algorithms can achieve a utility result, arbitrarily close to optimal value. Finally, the performance of the proposed control policies is validated with various network conditions.