System and method for securing a computer communication network

• US 6,865,672 B1
• Filed: 04/28/1999
• Issued: 03/08/2005
• Est. Priority Date: 05/18/1998
• Status: Expired due to Fees

• Current Assignee: Spearhead Technologies Ltd.
• Original Assignee: Spearhead Technologies Ltd.
• Inventors: Carmeli, Haim Baruch
• Primary Examiner(s): Darrow, Justin T.
• Assistant Examiner(s): Zand, Kambiz
• Application Number:
  US09/301,113
• Time in Patent Office: 2,141 Days
• Field of Search: 713153-155
• US Class Current: 713/155
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04L 63/145 the attack involving the propagation of malware through the network, e.g. viruses, trojans or worms

Abstract

A system for providing a trusted computer communication network including a master decision maker unit coupled to the trusted network; and at least one slave communication unit coupled to the master unit by a wide bus connection that has multiple unidirectional communication channels, and connected to a non-trusted network; wherein the trusted network is physically isolated at all times from the non-trusted network, and all data transported between the trusted network and the non-trusted network is transported between the master unit and the slave unit.

Claims

1. A system for securing a trusted computer communication network comprising:

a master decision maker unit coupled to the trusted network; and

at least one slave communication unit coupled to the master unit by a wide bus connection that has multiple unidirectional communication channels, said slave communication unit being further connected to a non-trusted network;

characterized in that;

(i) a chip based circuit is provided between said trusted network and said non-trusted network thereby keeping said networks is physically and logically disconnected from each other at all times, by preventing data streaming therebetween;

(ii) all data transported between the trusted network and said non-trusted network is transported between said master unit and said slave unit in static form;

(iii) all data transported between the trusted network and said non-trusted network is transported through unidirectional communication channels, using a handshake mechanism solely controlled by said trusted side, thereby preventing data streaming therebetween.

2. The system according to claim 1, wherein said master unit includes a master computer coupled for standard computer communication with the trusted network, and coupled via a standard computer bus to a master wide bus gate card;

and

said slave unit includes a slave wide bus gate card coupled via a wide bus connection that has multiple unidirectional communication channels to said master wide bus gate card and via a computer bus to a slave computer which, in turn, is connected to said non-trusted network for standard computer communication.

3. The system according to claim 1, wherein the system further includes a second slave unit coupled between the trusted network and said master unit.

4. The system according to claim 3, wherein said second slave unit includes a second slave wide bus gate card coupled via a wide bus connection that has multiple unidirectional communication channels to a second master wide bus gate based card and via a computer bus to a second slave computer which, in turn, is connected to said trusted network for standard computer communication.

5. The system according to claim 2, wherein said computer includes a Single Board Computer, and said wide bus gate card includes a Field Programmable Gate Array (FPGA).

6. The system according to claim 2, wherein said computer includes a Single Board Computer, and said wide bus gate card includes an Application Specific Integrated Circuit (ASIC).

7. The system according to claim 2, wherein said wide bus gate card includes a CPU.

8. The system according to claim 1, wherein said non-trusted network is the Internet.

9. The system according to claim 1, wherein all data is encrypted using a data signature causing the data to become static data wherein static data is meaningless and non-executable.

10. The system according to claim 1, wherein all data is transported in message form between said master unit and said slave unit.

11. The system according to claim 1, further comprising an additional unit, connected to either said master unit or one of said slave units, to perform computations and help reach security decisions.

12. The system according to claim 1, further comprising a physically isolated De-Militarized Zone (DMZ) network coupled to said master decision maker unit.

13. A method for securing a trusted computer communication network while allowing data to pass between said trusted computer communication network and a non trusted network, comprising the steps of:

a. disconnecting the trusted network from all non-trusted computer networks;

b. inserting a system between the trusted network and non-trusted network that maintains a physical and logical disconnection between said trusted network and non-trusted network at all times by preventing data streaming therebetween yet allows passage of data thereacross;

c. enabling transportation of data between said trusted network and said non-trusted network only with approval of said master decision maker using a handshake mechanism and thereby preventing data streaming therebetween

wherein said system comprises

a master decision maker unit coupled to the trusted network and to a slave communication unit;

said master unit including a master computer and a master wide bus gate card;

said slave unit including a slave computer and a slave wide bus gate card;

said master unit being connected to said slave unit by a wide bus connection connecting said master wide bus gate card to said slave wide bus gate card;

and said wide gate cards including a chip based circuit that only allows static data to pass therethrough.

14. The method according to claim 13, further including the steps of:

(i) initiating a data import process by said master unit or by said slave communication unit with approval of said master unit;

(ii) transporting data from said non-trusted network to said slave computer;

(iii) receiving said data from said non-trusted network at said slave computer;

(iv) signing said data with data signature thereby causing data to become static;

transporting said signed data form said slave wide bus gate card to said master computer;

(v) pulling said signed data and said data signature from said slave computer by said slave wide bus gate card;

(vi) pushing said data to the master wide bus gate card while simultaneously calculating and verifying the data signature by said slave wide bus gate card;

(vii) verifying, by said slave wide bus gate card, that the computed accumulated data signature subsequent to termination of the pulling of said signed data is correct; and

, where said data signature is allowed, signaling allowance to said master wide bus card, but where said accumulated data signature is not allowed, providing a delete command to said master wide bus card in accordance with the result of said step of verifying;

(viii) encoding said data using a key generated by and known only to said master wide bus gate card;

vii) transporting said encoded data from said master wide bus gate card to said master computer;

(viii) verifying said data signature;

(ix) examining said data in said master computer or providing a delete command or transporting allowable data to trusted network in accordance with the result of said step of verifying said data signature.

15. The method according to claim 14, wherein said step of examining includes examining said encoded data while it is still encoded.

16. The method according to claim 14, wherein said step of examining includes:

providing said key from said master wide bus gate card to said master computer;

decoding said encoded data; and

examining said decoded data.

17. The method according to claim 13, further including the steps of

initiating a data export process by said master unit or by said slave unit with the approval of said master unit;

transporting data from a data owner in the trusted network to said master computer;

signing said data with a data signature;

transporting said data from said master computer to said master wide bus gate card;

transporting said data from said master wide bus gate card to said slave wide bus gate card;

encoding said data using a key generated by and known only to said slave wide bus gate card;

transporting said encoded data from slave wide bus gate card to said slave computer;

verifying said data signature;

and transporting said data from slave computer to said non-trusted network or deleting said data, in accordance with the results of verifying said data signature.

18. The method according to claim 17, further including the step of examining said data in said master computer to authenticate said data owner after said step of signing.

19. The method according to claim 14, further comprising the step of examining, in said master unit, the data to be transported before transporting said data to or from the trusted network.

20. The method according to claim 17, further comprising the step of examining, in said master unit, the data to be transported before transporting said data to or from the trusted network.

21. The method according to claim 19, further including the step of reading said data to be transported as static data, and wherein said step of examining includes examining said static data for improper authorization and hostile programs.

22. The method according to claim 20, further including the step of reading said data to be transported in static data form, and wherein the step of examining includes examining each static data for improper authorization and owner authentication.

23. The method according to claim 13, wherein the non-trusted network is the Internet.

24. The method according to claim 23, further including the steps of:

inputting a list of sites to be imported into said master unit;

causing said master unit to instruct said slave unit to import specific site data;

examining said site data; and

copying said site data into the trusted network.

25. The method according to claim 13, wherein said non-trusted network includes a fax server.

26. The method according to claim 13, further comprising the steps of importing confidential files from all over the trusted network into a backup network, that is coupled only to said master unit or said slave unit.

27. The method according to claim 13, further comprising the steps of:

encrypting data to be passed through said master unit or said slave unit over an encrypted channel;

causing the unit which receives said encrypted data over the encrypted channel internally to decrypt said data;

examining said decrypted data for hostile content; and

if there is no hostile content, encrypting said data and passing said encrypted data through said unit which receives the data.

28. A method for securing a trusted computer communication network while allowing data to pass between said trusted computer communication network and a non trusted network, comprising the steps of:

disconnecting the trusted network from all non-trusted computer networks;

inserting a system between the trusted network and non-trusted network that maintains a physical and logical disconnection therebetween at all times by preventing data streaming therebetween yet allows passage of data thereacross;

wherein said system comprises

a master decision maker unit coupled to the trusted network and to a slave communication unit;

said master unit including a master computer and a master wide bus gate card;

said slave unit including a slave computer and a slave wide bus gate card;

said master unit being connected to said slave unit by a wide bus connection connecting said master wide bus gate card to said slave wide bus gate card;

and said wide gate cards including a chip based circuit that only allows static data to pass therethrough;

wherein all data import processes into said trusted network occur over said wide bus connection through said chip based circuit, in accordance with the following steps;

(i) initiating a data import process by said master unit or by said slave unit subject to approval of said master unit and thereby enabling transportation of data between said trusted network and said non-trusted network only with approval of said master unit;

(ii) receiving said data from said non-trusted network at said slave computer;

(iii) signing said data with data signature thereby causing data to become static

(iv) pulling said static data and said data signature from said slave computer by said slave wide bus gate card;

(v) pushing said signed static data to the master wide bus gate card while simultaneously calculating and verifying the data signature by said slave wide bus gate card;

(vi) verifying by said slave wide bus gate card that the computed accumulated data signature subsequent to termination of the pulling of said signed data is correct; and

, where said data signature is allowed, signaling allowance to said master wide bus card, but where said accumulated data signature is not allowed, providing a delete command to said master wide bus card in accordance with the result of said step of verifying;

(vii) encoding said data using a key generated by and known only to said master wide bus gate card;

(vii) transporting said encoded data from said master wide bus gate card to said master computer;

(viii) verifying said data signature, and if allowed, examining said data by said master computer, however, if said data signature is not allowed, providing a delete command;

(ix) said step of examining includes

(a) providing said key from said master wide bus gate card to said master computer;

(b) decoding said encoded data by said master computer;

(c) examining said decoded data by said master computer, and

(d) providing said allowable data to said trusted network.