Secure Encoding Strategy for Consensus of Multi-Agent Systems in the Presence of Eavesdropper

This brief studies consensus problem of single-integrator multi-agent network in the presence of eavesdropper. In the network, agents communicate with each other through digital communication channels, and the eavesdropper overhears the messages transmitted by the agents over wiretap channels. A secure encoding strategy based on constructing auxiliary systems is designed to ensure that the multi-agent network achieves consensus, while the eavesdropper cannot precisely estimate the state of any agent in the network. To defend against eavesdropping, each agent in the network transmits the state of its constructed auxiliary system instead of its state value to its neighbors. A sufficient condition of consensus and security is given by studying the relationship between topological entropy and the maximum transmission rates. A simulation example is given to illustrate the effectiveness of the encoding strategy.