The technical principles of protection systems involve various defense strategies, such as active protection and defense-in-depth.
Taking an active protection system for armored vehicles as an example, its operating mechanism is as follows: It uses radar and photoelectric detection devices to sense and acquire the trajectory and characteristics of incoming munitions. Then, a computer controls countermeasures to conduct targeted self-defense. Based on the differences in their mechanisms, they can be divided into three main categories: soft-kill systems (jamming and decoy systems), which use smoke grenades, jammers, and decoys to deceive and interfere with incoming munitions; hard-kill systems (ballistic interception systems), which launch interceptor munitions to track, intercept, and destroy incoming munitions; and integrated defense systems, which are comprehensive protection systems that combine both soft and hard kill methods.
In critical information infrastructure fields such as industrial control systems (e.g., power monitoring systems), defense-in-depth strategies are often adopted. Its core principle draws on the protection concepts of "security zoning, dedicated networks, horizontal isolation, and vertical authentication." By dividing security zones, implementing dedicated and isolated networks, and enforcing mandatory access control and authentication between zones, a defense-in-depth system consisting of multiple lines of defense is constructed to counter cyberattacks.
For emerging computing environments such as artificial intelligence (e.g., intelligent agents), the protection system aims to build security capabilities covering their entire lifecycle. Its principles typically involve constructing a core architecture across multiple layers, including secure access, secure operation, secure trapping, and a secure control system. Through mechanisms such as endpoint security management, vulnerability patching, access control, induction identification, and logical defense, it achieves the protection goals of "prevention before the event, control during the event, and traceability after the event."
