US Patent 11176252 Intrusion prevention device, intrusion prevention method, and intrusion prevention program

An intrusion prevention device includes a reception unit, a monitoring unit, and a determination unit. The reception unit receives, from a control target device, a notification indicating a state of the control target device. The monitoring unit receives a control command transmitted from a control device to the control target device. The determination unit determines whether to permit or block passage of the control command received by the monitoring unit in accordance with the state of the control target device received by the reception unit.