Abstract: A first message from a remote terminal unit (RTU) is received, where the first message indicates that a motion has been detected. In response to receiving the first message, a timer is started at a supervisory control and data acquisition (SCADA) server. Whether a personal identification number (PIN) verification and a radio-frequency identification (RFID) verification have succeeded is determined before the timer expires. In response to determining that at least one of the PIN verification or the RFID verification fails, a communication port connecting the RTU with the SCADA server is disabled.