Method and system for updating a root of trust measurement function in a personal computer

• US 6,782,349 B2
• Filed: 05/03/2002
• Issued: 08/24/2004
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Gettelfinger, Chad Lee, Springfield, Randall Scott, Goodman, Steven Dale, Challener, David Carroll, Ward, James Peter, Ovies, Hernando
• Primary Examiner(s): Assouad, Patrick
• Application Number:
  US10/063,608
• Publication Number:
  US 20030208338A1
• Time in Patent Office: 844 Days
• Field of Search: 702/186, 713/187, 713/191, 713/193, 713/194, 713/100, 713/1
• US Class Current: 702/186
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database

Abstract

A method and system for updating a root of trust measurement (RTM) function in a personal computer is disclosed. The RTM function is located in a boot block of the personal computer. The method and system comprise initializing a request to update the RTM function and unlocking the boot block based on an authentication process. The method and system further includes updating the RTM function. Through the use of the method and system in accordance with the present invention, the RTM function in a personal computer is updated in a manner that ensures that the update is authentic.

Claims

1. A method for updating a root of trust measurement (RTM) function in a personal computer, the RTM function being located in a boot block of the personal computer, the method comprising the steps of:

a) initializing a request to update the RTM function, wherein step a) further comprises;

a1) detecting the request to update the RTM function; and

a2) storing a new RTM function within a file on a local storage media;

b) unlocking the boot block based on an authentication process; and

c) updating the RTM function.

2. The method of claim 1 wherein the local storage media comprises a diskette or a hardfile.

3. The method of claim 2 wherein step a) further comprises:

a3) passing the request to the boot block;

a4) updating a POST sequence; and

a5) rebooting the computer.

4. The method of claim 3 wherein step a3) further comprises:

a3i) passing the request and a pointer to the file via a secure communications buffer within the computer.

5. The method of claim 1 wherein step b) further comprises:

b1) allowing the boot block to detect the request;

b2) authenticating a digital signature of a POST sequence related to the request; and

b3) allowing the boot block to remain unlocked.

6. The method of claim 4 wherein step b) further comprises:

b1) allowing the boot block to detect the request;

b2) authenticating a digital signature of the POST sequence used in step a5); and

b3) allowing the boot block to remain unlocked.

7. The method of claim 1 wherein step c) further comprises:

c1) detecting the request to update the RTM function;

c2) authenticating the request to update the RTM function; and

c3) verifying a digital signature of a new RTM function.

8. The method of claim 7 wherein step c) further comprises:

c4) replacing the RTM function with the new RTM function; and

c5) rebooting the computer utilizing the new RTM function.

9. The method of claim 6 wherein step c) further comprises:

c1) detecting the request to update the RTM function;

c2) authenticating the request to update the RTM function; and

c3) verifying a digital signature of a new RTM function.

10. The method of claim 9 wherein step c) further comprises:

c4) replacing the RTM function with the new RTM function; and

c5) rebooting the computer utilizing the new RTM function.

11. The method of claim 10 wherein the personal computer is a Trusted Computing Platform Alliance (TCPA) compliant personal computer.

12. A system for updating a root of trust measurement (RTM) function in a personal computer, the RTM function being located in a boot block of the personal computer, comprising:

means for initializing a request to update the RTM function, wherein the means for initializing a request further comprises;

means for detecting the request to update the RTM function; and

means for storing a new RTM function within a file on a local storage media;

means for unlocking the boot block based on an authentication process; and

means for updating the RTM function.

13. The system of claim 12 wherein the local storage media comprises a diskette or a hardfile.

14. The system of claim 13 wherein the means for initializing a request further comprises:

means for passing the request to the boot block;

means for updating a POST sequence; and

means for rebooting the computer.

15. The system of claim 14 the means for passing the request to the boot block further comprises:

means for passing the request and a pointer to the file via a secure communications buffer within the computer.

16. The system of claim 12 wherein the means for initializing a request further comprises:

means for allowing the boot block to detect the request;

means for authenticating a digital signature of a POST sequence related to the request; and

means for allowing the boot block to remain unlocked.

17. The system of claim 15 wherein the means for initializing a request further comprises:

means for allowing the boot block to detect the request;

means for authenticating a digital signature of the POST sequence.

18. The system of claim 12 wherein the means for updating the RTM function further comprises:

means for detecting the request to update the RTM function;

means for authenticating the request to update the RTM function; and

means for checking a digital signature of a new RTM function.

19. The system of claim 18 wherein the means for updating the RTM function further comprises:

means for replacing the RTM function with the new RTM function; and

means for rebooting the computer utilizing the new RTM function.

20. The system of claim 17 wherein the means for updating the RTM function further comprises:

means for detecting the request to update the RTM function;

means for authenticating the request to update the RTM function; and

means for checking a digital signature of a new RTM function.

21. The system of claim 20 wherein the means for updating the RTM function further comprises:

means for replacing the RTM function with the new RTM function; and

means for rebooting the computer utilizing the new RTM function.

22. The system of claim 21 wherein the personal computer is a Trusted Computing Platform Alliance (TCPA) compliant personal computer.

23. A computer readable medium containing program instructions for updating a root of trust measurement (RTM) function in a personal computer, the RTM function being located in a boot block of the personal computer, the program instructions for:

a) initializing a request to update the RTM function;

b) allowing the boot block to remain unlocked based on an authentication process; and

c) updating the RTM function.

24. The computer readable medium of claim 23 wherein step a) further comprises:

a1) detecting the request to update the RTM function; and

a2) storing a new RTM function within a file on a local storage media.

25. The computer readable medium of claim 24 wherein the local storage media comprises a diskette or a hardfile.

26. The computer readable medium of claim 25 wherein step a) further comprises:

a3) passing the request to the boot block;

a4) updating a POST sequence; and

a5) rebooting the computer.

27. The computer readable medium of claim 26 wherein step a3) further comprises:

a3i) passing the request and a pointer to the file via a secure communications buffer within the computer.

28. The computer readable medium of claim 23 wherein step b) further comprises:

b1) allowing the boot block to detect the request;

b2) authenticating a digital signature of a POST sequence related to the request; and

b3) allowing the boot block to remain unlocked.

29. The computer readable medium of claim 28 wherein step b) further comprises:

b1) allowing the boot block to detect the request;

b2) authenticating a digital signature of the POST sequence used in step a5); and

b3) allowing the boot block to remain unlocked.

30. The computer readable medium of claim 23 wherein step c) further comprises:

c1) detecting the request to update the RTM function;

c2) authenticating the request to update the RTM function; and

c3) verifying a digital signature of a new RTM function.

31. The computer readable medium of claim 30 wherein step c) further comprises:

c4) replacing the RTM function with the new RTM function; and

c5) rebooting the computer utilizing the new RTM function.

32. The computer readable medium of claim 29 wherein step c) further comprises:

c1) detecting the request to update the RTM function;

c2) authenticating the request to update the RTM function; and

c3) verifying a digital signature of a new RTM function.

33. The computer readable medium of claim 32 wherein step c) further comprises:

c4) replacing the RTM function with the new RTM function; and

c5) rebooting the computer utilizing the new RTM function.

34. The computer readable medium of claim 33 wherein the personal computer is a Trusted Computing Platform Alliance (TCPA) compliant personal computer.