Abstract: An encrypted control system, an encrypted control method, and an encrypted control program make it possible to further reduce a risk of a cipher key leaking. An input device, a plant-side control device, and a controller are respectively equipped with pseudorandom number calculation units having a common function, are time synchronized, and start a synchronized operation at the same time. Since the encrypted control system is configured in such a manner, it becomes possible to switch a pair of a public key and a private key in synchronization with a control cycle of the entire control system. Consequently, it becomes possible to instantaneously and definitely detect intervention in the control system by a malicious third party.

Abstract: An encrypted control system, an encrypted control method, and an encrypted control program make it possible to further reduce a risk of a cipher key leaking. An input device, a plant-side control device, and a controller are respectively equipped with pseudorandom number calculation units having a common function, are time synchronized, and start a synchronized operation at the same time. Since the encrypted control system is configured in such a manner, it becomes possible to switch a pair of a public key and a private key in synchronization with a control cycle of the entire control system. Consequently, it becomes possible to instantaneously and definitely detect intervention in the control system by a malicious third party.

Abstract: Providing a remote control technique capable of realizing the achievement of constraints and the certain following of a target value even with a network in which delay, loss, distortion, or the like may occur. In a remote control system, an area setting unit of a client-side control unit sets at least two areas representative of a group of states of an target object, which changes over time by feedback control. A state-evaluation information sending unit sends, to the host-side control unit, state evaluation information obtained by evaluating the state of the target object based on the area set by the area setting unit. A target value setting unit of the host-side control unit sets a target value such that the state of the target object changes in the area set by the area setting units. Moreover, a target value updating unit updates the target value based on the state evaluation information received from the client-side control unit.

Abstract: Providing a remote control technique capable of realizing the achievement of constraints and the certain following of a target value even with a network in which delay, loss, distortion, or the like may occur. In a remote control system, an area setting unit of a client-side control unit sets at least two areas representative of a group of states of an target object, which changes over time by feedback control. A state-evaluation information sending unit sends, to the host-side control unit, state evaluation information obtained by evaluating the state of the target object based on the area set by the area setting unit. A target value setting unit of the host-side control unit sets a target value such that the state of the target object changes in the area set by the area setting units. Moreover, a target value updating unit updates the target value based on the state evaluation information received from the client-side control unit.