Robust Finite-Horizon H _∞ Filtering for Complex Networks Under Replay Attacks

This paper addresses the issue of robust finite-horizon H∞ filtering for complex networks subject to replay attacks. A replay attack strategy is implemented by the adversary on the communication channel between the network nodes and the filters, with the intention of replacing the current measurement data with previously recorded measurement data. Considering the limited energy of the attacker, a binary variable is adopted to indicate whether the communication channel is under attack. To better characterize the dynamic behavior of replay attacks, two factors dependent on attack frequency and a time-varying parameter are introduced. Subsequently, under the impact of replay attacks, the switched filtering error dynamics is obtained with a time-varying delay. By employing the average dwell-time method, sufficient conditions are derived to guarantee the weighted H∞ performance of the filtering error dynamics. Furthermore, the filter gain parameters are computed through the solution of some recursive matrix inequalities. Finally, numerical simulation results are conducted to verify that the developed filter design algorithm is effective.