Data diode system

• US 8,250,358 B2
• Filed: 04/01/2009
• Issued: 08/21/2012
• Est. Priority Date: 04/01/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Cheng, Kelvin Y.
• Primary Examiner(s): Goodarzi, Nasser
• Assistant Examiner(s): Traore, Fatoumata
• Application Number:
  US12/416,831
• Publication Number:
  US 20100257353A1
• Time in Patent Office: 1,238 Days
• Field of Search: None
• US Class Current: 713/153
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/071 adapted to generate a negative voltage output from a positive voltage source
• CPC Class Codes: H04L 63/0209 Architectural arrangements, e.g. perimeter networks or demilitarized zones
• CPC Class Codes: H04L 63/105 Multiple levels of security

Abstract

A data diode system enables one-way data flow from an unsecured device to a secured device is disclosed. The data diode system includes at least one data diode that convert a communication received from an unsecured device to a secured communication for transmission to the secured device. The data diode system includes a voltage converter that receives a negative voltage from a serial data port connection of the secured device. The voltage converter converts the negative voltage into a positive voltage in order to power the data diode.

Claims

1. A data diode system for transferring a communication from an unsecured network to a secured network, the system comprising:

a DC converter configured to receive a negative DC voltage from a serial data connection of the secured network and to convert the negative DC voltage to a positive DC voltage;

a data diode circuit configured to;

receive the positive DC voltage from the DC converter to power the data diode circuit;

receive a communication from the unsecured network;

generate a secured communication in response to the communication; and

transmit the secured communication to the secured network.

2. The system of claim 1 wherein:

the unsecured network comprises an unsecured communication device connected to an unsecured communication network; and

the secured network comprises a secured communication device connected to a secured communication network;

wherein the communication is generated at the unsecured communication device and transmitted to the data diode circuit via the unsecured communication network; and

wherein the secured communication is transmitted to the secured communication device via the unsecured communication network.

3. The system of claim 2 wherein:

the unsecured communication device comprises a first data transmit connection, a first ground connection, and a first data receive connection; and

the secured communication device comprises a second data transmit connection, a second ground connection, and a second data receive connection;

wherein the communication is transmitted from the first data transmit connection to the data diode circuit; and

wherein the secured communication is transmitted from the data diode circuit to the second data receive connection.

4. The system of claim 3 wherein the DC converter receives the negative DC voltage from the second data transmit connection.

5. The system of claim 3 wherein the DC converter is further configured to transmit the negative DC voltage and wherein the data diode circuit comprises:

a first opto-coupler configured to;

receive the communication from the first data transmit connection;

receive the positive DC voltage from the DC converter; and

generate the secured communication in response to the communication and the positive DC voltage when the first data connection is at a negative voltage in reference to the first ground connection; and

a second opto-coupler configured to;

receive the communication from the first data transmit connection;

receive the negative DC voltage from the second data transmit connection; and

generate the secured communication in response to the communication and the negative DC voltage when the first data connection is at a negative voltage in reference to the first ground connection.

6. The system of claim 5 wherein the DC converter comprises a third ground connection, a voltage input connection, a positive voltage output connection, and wherein:

the third ground connection is connected to the second data transmit connection;

the voltage input connection is connected to the second ground connection; and

the positive voltage output connection is connected to a positive voltage input of the first opto-coupler.

7. The system of claim 5 further comprising a resistor connected between the second data transmit connection and the second ground connection, wherein the resistor maintains the negative DC voltage at the second data receive connection when the unsecured device is disconnected from the data diode system.

8. The system of claim 7 wherein the resistor has a resistance between to 90 to 110 kilo-ohms.

9. The system of claim 1 wherein the data diode circuit and the DC converter are housed in an enclosure that is configured to be attached or fitted to a user of the secured communication device.

10. A data diode system for transferring a communication from an unsecured communication device to a secured communication device, the system comprising:

a DC converter configured to;

receive a negative DC voltage from a serial connection of the secured communication device; and

convert the negative DC voltage into a positive DC voltage;

a data diode circuit configured to;

receive the positive DC voltage from the DC converter to power the data diode circuit;

receive the communication from a data port of the unsecured communication device, the data port comprising a first data transmit connection, a first ground connection, and a first data receive connection;

generate a secured communication in response to the communication and the received positive DC voltage; and

transmit the secured communication to the secured communication device.

11. The system of claim 10 wherein:

the secured communication device comprises a second data transmit connection, a second ground connection, and a second data receive connection;

wherein the communication is transmitted from the first data transmit connection to the data diode circuit; and

wherein the secured communication is transmitted from the data diode circuit to the second data receive connection.

12. The system of claim 11 wherein the DC converter receives the negative DC voltage from the second data transmit connection.

13. The system of claim 11 wherein the DC converter is further configured to transmit the negative DC voltage and wherein the data diode circuit comprises:

a first opto-coupler configured to;

receive the communication from the first data transmit connection;

receive the positive DC voltage from the DC converter; and

generate the secured communication in response to the communication and the positive DC voltage when the first data connection is at a positive voltage in reference to the first ground connection; and

a second opto-coupler configured to;

receive the communication from the first data transmit connection;

receive the negative DC voltage from the second transmit connection; and

generate the secured communication in response to the communication and the negative DC voltage when the first data connection is at a positive voltage in reference to the first ground connection.

14. The system of claim 13 wherein the DC converter comprises a third ground connection, a voltage input connection, and a positive voltage output connection, and wherein:

the third ground connection is connected to the second data transmit connection;

the voltage input connection is connected to the second ground connection;

the positive voltage output connection is connected to a positive voltage input of the first opto-coupler; and

the second data transmit connection is connected to a negative voltage input of the first opto-coupler.

15. The system of claim 13 further comprising:

a resistor connected between the second data transmit connection and the second ground connection;

wherein the resistor maintains the negative DC voltage at the second data receive connection when the unsecured device is disconnected from the data diode system; and

wherein the resistor has a resistance between to 90 to 110 kilo-ohms.

16. The system of claim 10 wherein the data diode circuit and the DC converter are housed in an enclosure that is configured to be attached or fitted to a user of the secured communication device.

17. A method for transferring a communication from an unsecured network to a secured network comprising:

receiving a communication at a data diode system from the unsecured network, the data diode system comprising a DC converter and a data diode circuit;

receiving a negative DC voltage at the DC converter from a serial data connection of the secured network;

converting the negative DC voltage to a positive DC voltage at the DC converter;

receiving the positive DC voltage at the data diode circuit;

generating a secured communication at the data diode circuit in response to the communication and the received positive DC voltage; and

transmitting the secured communication to the secured network.

18. The method of claim 17 wherein:

the unsecured network comprises an unsecured communication device connected to an unsecured communication network; and

the secured network comprises a secured communication device connected to a secured communication network; and

the method further comprises;

generating the communication at the unsecured communication device;

transmitting the communication to the data diode circuit via the unsecured communication network; and

transmitting the secured communication to the secured communication device via the secured communication network.

19. The method of claim 18 wherein:

the unsecured communication device comprises a first data transmit connection, a first ground connection, and a first data receive connection; and

the secured communication device comprises a second data transmit connection, a second ground connection, and a second data receive connection; and

the method further comprises;

transmitting the communication from the first data transmit connection to the data diode circuit; and

transmitting the secured communication from the data diode circuit to the second data receive connection.

20. The method of claim 19 further comprising receiving the negative DC voltage at the DC converter from the second data transmit connection.

21. The method of claim 19 wherein the data diode circuit comprises a first opto-coupler and a second opto-coupler configured;

and

the method further comprises;

receiving the communication at the first opto-coupler from the first data transmit connection;

receiving the positive DC voltage from the DC converter to power the data circuit;

generating the secured communication in response to the communication and the positive DC voltage when the first data connection is at a positive voltage in reference to the first ground connection;

receiving the communication at the second opto-coupler from the first data transmit connection;

receiving the negative DC voltage from the second transmit data connection;

generating the secured communication in response to the communication and the positive DC voltage when the first data connection is at a negative voltage in reference to the first ground connection; and

transmitting the secured communication to the second data receive connection.

22. The method of claim 21 wherein:

the DC converter comprises a third ground connection, a voltage input connection, and a positive voltage output connection, and

the method further comprising;

receiving a ground potential at the voltage input connection from the second ground connection;

receiving the negative voltage at the third ground connection from the second data transmit connection; and

supplying the positive voltage to a positive voltage input of the first opto-coupler from the positive voltage output connection.

23. The method of claim 17 wherein the data diode circuit and the DC converter are housed in an enclosure and the method further comprises attaching or fitting the enclosure to a user of the secured communication device.