External terminal protection device and protection system

An external terminal protection device, comprising:

• an interface control module, used for providing one or more internal interfaces and one or more external interfaces, the internal interfaces being connected to a corresponding interface of a protected host, and the external interfaces being configured to access one or more external devices;
• a system control module, used for electrically connecting the interface control module, controlling security authentication of the external device accessed to the one or more external interfaces on the interface control module, so as to determine whether the external device is a licensed external device, setting the external device to be an unlicensed access device and keeping a circuit between the external device and the protected host in a physically disconnected state if the external device does not pass the security authentication, and determining that the external device is a licensed access device and switching on a physical connection of the circuit between the external device and the protected host if the external device passes the security authentication;
• an internal memory, used for storing data exchanged between the interfaces, storing a preset security policy, and performing security authentication on different types of interfaces or interfaces with different serial numbers on the interfaces control module by reading the preset security policy stored in the internal memory;
• wherein the interface control module is further used for notifying the system control module that the system control module performs a security authentication operation on the external device when the external interface of the interface control module accesses the external device;
• and
• the interface control module is further used for monitoring in real time a connection state of the internal interface connected to the corresponding interface of the protected host, automatically triggering, when the connection state is abnormal, the disconnection of a circuit between the interface control module and the protected host, to be specific, capturing a current/voltage change of the internal interface via a monitoring circuit, determining that the connection state is abnormal, and triggering an alarm indication signal, and restoring the connection state from abnormality to normality after the disconnection of the circuit between the interface control module and the protected host is automatically triggered, and still keeping the circuit between the interface control module and the protected host in the disconnected state.