I. Introduction
NETWORKS are ubiquitous in the real world [1], [2]. In many infrastructures, nodes are interconnected to form complex networks [3]–[6] that realize the transfer and transmission of flow to maintain functions, such as traffic flow, power flow and information flow. In recent decades, with the development of communication, computer and control (3 C) technologies, a large number of physical devices are equipped with intelligent electronic devices (IEDs) [7], [8]. In the Internet of Things (IoT) [9], in addition to physical systems (networks), additional communication and control systems (networks) are also required to form cyber-physical systems (CPSs) [10]. Among them, the physical network is the main body of the system, which is responsible for the realization of physical functions, such as power supply and communication. As an auxiliary system of the physical network, the cyber (information) network is responsible for status monitoring and data transmission of the physical system as well as optimization and command issuing from the control center. For example, in cyber-physical power systems (CPPSs) [11], [12], the power grid realizes the generation and transmission of electricity, and the cyber network enables the monitoring of power nodes and the optimization of power flow. Similarly, in cyber-physical transportation systems, the cyber network facilitates the control and optimization of traffic flow, such as the control of traffic lights and the evacuation of congested roads.