Computer architecture for an electronic device providing a secure file system

• US 8,127,145 B2
• Filed: 03/23/2006
• Issued: 02/28/2012
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: Nera Innovations Limited (Atlantic IP Services Limited)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: O'Brien, Terence W., Schmalbach, Richard, Blessing, John, Murray, Jeffrey L.
• Primary Examiner(s): Orgad, Edan
• Assistant Examiner(s): OLION, BRIAN L
• Application Number:
  US11/387,342
• Publication Number:
  US 20070226517A1
• Time in Patent Office: 2,168 Days
• Field of Search: 713/189, 713/193, 726/26
• US Class Current: 713/189
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G06F 2221/2113 Multi-level security, e.g. mandatory access control

Abstract

A secure file service includes a cryptographic processor (302, 602) and a secure file system (301, 601). The cryptographic processor is comprised of a trusted microprocessor and a trusted operating system executing on the trusted cryptographic processor. The cryptographic processor includes hardware and software for accessing at least one classified data file from the secure file system, decrypting the classified data file, and serving the classified data file in decrypted form to a secure user processor (402, 502, 702) that has requested the file. The secure file system can be either a single-level secure file system (301) or a multi-level secure file system (601).

Claims

1. A method for providing a secure file service, comprising:

providing a computer system for operation in an unsecure environment, said computer system comprising a secure file services module and a secure user processor which is separate and distinct from said secure file services module, each configured to secure data contained therein wherein said secure file services module and said secure user processor are embodied on the same computing device;

providing first and second secure communication paths in said unsecure environment directly between said secure file services module and said secure user processor, said first secure communication path being separate from said second secure communication path and configured to physically secure data communicated thereover by employing physically secure communication path hardware, said second secure communication path configured to exclusively support user sign-on services and to only software secure data communicated thereover;

communicating an authentication request to said secure file services module over said second secure communication path, said secure file services module including a file system control interface, a client access interface, a cryptographic processor and a secure file system hosted by said cryptographic processor;

providing an authentication of said user using said file system control interface;

communicating to said client access interface over said first secure communication path a request from said secure user processor for a classified data file;

responsive to said request, accessing said secure file system containing said classified data file;

decrypting said classified data file with said cryptographic processor;

and communicating said classified data file to said secure user processor in decrypted form through said first secure communication path.

2. The method according to claim 1, further comprising selecting said cryptographic processor to include one or more hardware based encryption services that facilitate the encryption and decryption of classified data files.

3. The method according to claim 2, further comprising selecting said hardware based encryption services from the group consisting of a hardware implemented cryptographic algorithm, a random number generator, and an exponentiator.

4. The method according to claim 1, further comprising selecting said secure file system from the group consisting of a single-level secure file system and a multi-level secure file system.

5. The method according to claim 1, further comprising generating said request for said classified data file at a secure human/machine interface and communicating said request to said secure user processor.

6. The method according to claim 1, further comprising, displaying information contained in said classified data file to a user with a secure human/machine interface.

7. The method according to claim 1, further comprising:

communicating said classified data file from said secure user processor to said client access interface through said first secure communication path;

encrypting said classified data file using said cryptographic processor; and

accessing said secure file system with said cryptographic processor to store said classified data file after encryption in said secure file system.

8. The method according to claim 1, wherein said communication of said authentication request further includes communicating at least one user authentication information to said cryptographic processor.

9. The method according to claim 1, further comprising:

receiving at said client access interface a request from said secure user processor for a non-encrypted unclassified data file;

responsive to said request, accessing with said cryptographic processor a secure file system containing said unclassified data file; and

communicating said unclassified data file to said secure user processor through said first secure communication path in plain-text form.

10. The method according to claim 1, further comprising selecting said cryptographic processor to include a trusted microprocessor and a trusted operating system executing on said trusted cryptographic processor.

11. The method according to claim 1, further comprising selecting said secure user processor to include a trusted microprocessor hardware.

12. The method according to claim 11, further comprising selecting said secure user processor to include a trusted operating system.

13. The method according to claim 11, further comprising selecting said secure user processor to include an untrusted operating system.

14. A system for providing a secure file service, comprising:

a computer system comprising a secure user processor configured to secure data contained

therein wherein said secure file services module and said secure user processor are embodied on the same computing device;

a secure file services module communicatively coupled to said computer system and comprising;

a cryptographic processor comprising means for encrypting and decrypting a classified data file; and

a secure file system hosted by said cryptographic processor containing classified data files stored in a classified information storage area thereof and unclassified data files stored in an unclassified information storage area thereof, said secure file system accessible exclusively to said cryptographic processor; and

first and second secure communication paths provided directly between said secure file services module and said secure user processor, said first secure communication path being separate from said second secure communication path and configured to physically secure data communicated thereover by employing physically secure communication path hardware;

said second secure communication path configured to exclusively support user sign-on services and to only software secure data communicated thereover;

wherein said cryptographic processor comprises a processing device responsive to said secure user processor distinct from said cryptographic processor for accessing at least one classified data file from said secure file system, decrypting said classified data file, communicating, from said cryptographic processor, said classified data file to said secure user processor in decrypted form, wherein said cryptographic processor is configured to prevent classified information of said classified data file from being written to said unclassified information storage area of said secure file system.

15. The system according to claim 14, wherein said cryptographic processor further comprises one or more hardware based encryption services that facilitate the encryption and decryption of classified data files.

16. The system according to claim 15, wherein said hardware based encryption services are selected from the group consisting of a hardware implemented cryptographic algorithm, a random number generator, and an exponentiator.

17. The system according to claim 14, wherein said secure file system is a single-level secure file system.

18. The system according to claim 14, further comprising a secure human/machine interface operatively connected to said secure user processor configured for communicating user commands to said secure user processor and for displaying classified data files.

19. The system according to claim 14, wherein said secure user processor further comprises processing means for communicating said classified data file from said secure user processor to said cryptographic processor.

20. The system according to claim 19, wherein said cryptographic processor further comprises processing means for encrypting said classified data file, and for accessing said secure file system with said cryptographic processor to store said classified data file after encryption in said secure file system.

21. The system according to claim 14, wherein at least one of said secure user processor and said cryptographic processor further comprises processing means for authenticating a user responsive to at least one user authentication information.

22. The system according to claim 14, wherein said cryptographic processor further comprises means for accessing a secure data file system responsive to a request from said secure user processor for an unclassified plain-text data file, and means for serving said unclassified data file to said secure user processor.

23. The system according to claim 14, wherein said cryptographic processor is comprised of a trusted microprocessor and a trusted operating system executing on said trusted cryptographic processor.

24. The system according to claim 14, wherein said secure user processor include a trusted microprocessor hardware.

25. The system according to claim 24, wherein said secure user processor is comprised of a trusted operating system.

26. The system according to claim 24, wherein said secure user processor comprises an untrusted operating system.

27. A system for providing a secure file service, comprising:

a secure file services module including

a cryptographic processor,

a cryptographic processor file system hosted by said cryptographic processor providing storage for files used exclusively by said cryptographic processor,

a secure file system hosted by said cryptographic processor wherein said secure the services module and said secure user processor are embodied on the same computing device, said secure file system

including a classified information storage area and an unclassified information storage area,

a client access interface configured to serve classified files stored in said secure file system to a client processor after decryption by said cryptographic processor, to receive classified files from said client processor, and to store said classified files in said secure file

system after encryption by said cryptographic processor, said client access interface comprising a first secure communication path directly between said secure file services module and said client processor that is configured to physically secure data communicated therethrough by employing physically secure communication path hardware, and

a file system control interface communicating with said cryptographic processor and, configured for authenticating a user prior to said client access interface serving classified files to said client processor, said file system control interface comprising a second secure communication path directly between said secure file services module and said client processor that is separate from said first secure communication path, said second secure communication path configured to exclusively support user sign-on services and to only software secure data communicated thereover.

28. The system according to claim 27, wherein said secure file system is a single level secure file system.

29. The system according to claim 28, wherein said client access interface provides said client processor with read only access to said unclassified information.

30. The system according to claim 28, wherein said client processor is comprised of trusted hardware and untrusted software.

31. The system according to claim 30, further comprising a human/machine interface comprised of trusted hardware which interfaces with the client processor over a physically secure data communication path.