System and method for secure unidirectional transfer of commands to control equipment
View Patent ↗A system for securely transferring commands to a recipient device. An access interface allows a user to enter a command for the recipient device. The access interface only allows the user to enter commands within a subset of commands associated with a role assigned to the user. The control interface receives information, i.e., the command entered by the user and the associated user role, from the access interface. The control interface outputs, to the manifest engine, the information and a manifest table which identifies each role and the subset of commands associated with each role. The manifest engine compares the information with the contents of the received manifest table, and, if the command entered by the user corresponds to a command within the set of commands associated with the role assigned to the user, forwards the command to the recipient device.
1. A system for securely transferring commands to a recipient control device, comprising:
an access interface configured to allow a user to enter a command, wherein the command comprises one of a set of commands for the recipient control device, wherein the user is assigned one of a predetermined set of roles, each role associated with a subset of the set of commands, wherein the access interface is configured to restrict the user to be able to enter only commands within the predetermined subset of commands associated with the assigned role;
a control interface coupled to receive information from the access interface, the information comprising the command entered by the user and the assigned role of the user, the control interface configured to output the information and a manifest table, the manifest table identifying each role and the subset of commands associated with each role; and
a manifest engine coupled to the control interface via a first communications link, the manifest engine comprising a manifest engine TX server computer and a manifest engine RX server computer coupled by a one-way data link in which data may only pass from an output of the manifest engine TX server computer to an input of the manifest engine RX server computer and an input of the manifest engine TX server computer configured to receive the information and the manifest table from the control interface via an input of the manifest engine, to compare the information with the contents of the received manifest table, and, if the command entered by the user corresponds to a command within the set of commands associated with the role assigned to the user, to forward the command on an output of the manifest engine RX server computer to the recipient control device, the output of the manifest engine RX server computer directly coupled to the recipient control device via a separate second communications link.
2. The system of claim 1 , wherein the control interface has two outputs, a first output for outputting the information and a second output for outputting the manifest table; and wherein the manifest engine has two inputs, a first input coupled to the first output of the control interface to receive the information and a second input coupled to the second output of the control interface to receive the manifest table.
3. The system of claim 1 , wherein recipient control device includes an output for providing status information, wherein the control interface is coupled to the output of the recipient control device via a separate connection, and wherein the control interface is configured to monitor the recipient control device based on status information received from the recipient control device.
4. The system of claim 3 , wherein the separate connection is a one-way data link in which information may only pass from the output of the recipient control device to the control interface.
5. The system of claim 1 , wherein the recipient control device has an output for providing status information, the system further comprising:
a second manifest engine having a first input coupled to the output of the recipient control device, a second input coupled to receive a second manifest table from the control interface, the second manifest table identifying a predetermined set of status information and an output coupled to the control interface, the second manifest engine configured to compare the status information received from the recipient control device with the contents of the received second manifest table, and, if the status information corresponds to status information within the predetermined set of status information identified in the manifest table, to forward the status information on the output.
6. The system of claim 5 , wherein the second manifest engine comprises:
a second manifest engine TX server computer having an input coupled to the output of the recipient control device and an output, and configured to forward any status information received at the input to the output;
a second data link having an input coupled to the output of the second manifest engine TX server computer and an output; and
a second manifest engine RX server computer having a first input coupled to the output of the second data link, a second input coupled to the control interface and an output coupled to the control interface;
wherein the second manifest engine RX server computer is configured to receive the second manifest table via the second input; and wherein the second manifest engine RX server computer is configured to receive status information forwarded by the second manifest engine TX server computer via the second data link and to compare the received status information with the contents of the received second manifest table and, if the received status information is identified in the second manifest table, to forward the received status information to the control interface via the output.
7. The system of claim 6 , wherein the second data link is a one-way data link in which data may only pass from the input to the output.