Systems and methods for controlling access to data on a computer with a secure boot process

• US 7,565,553 B2
• Filed: 01/14/2005
• Issued: 07/21/2009
• Est. Priority Date: 01/14/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Schwartz, Jonathan, England, Paul, Ray, Kenneth D., Thom, Stefan, Hunter, Jamie, Schwartz, James Anthony Jr., Humphries, Russell
• Primary Examiner(s): LAFORGIA, CHRISTIAN A
• Application Number:
  US11/036,415
• Publication Number:
  US 20060161790A1
• Time in Patent Office: 1,649 Days
• Field of Search: 726/9
• US Class Current: 713/192
• CPC Class Codes: G06F 21/575 Secure boot
• 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

Abstract

Systems and methods for controlling access to data on a computer with a secure boot process can provide a highly efficient mechanism for preventing future access to encrypted digital resources. This may be advantageous in a range of scenarios, for example where a computer is sold and assurance is desired that no stray private data remains on the hard disk. Data resources, for example all data associated with one or more particular hard disk partitions, may be encrypted. The decryption key may be available through a secure boot process. By erasing, altering, or otherwise disabling a secret, such as a decryption key or a process that obtains a decryption key, the data formerly accessible using such secret becomes inaccessible.

Claims

1. A computer comprising a mechanism for disabling access to at least one secret for booting an operating system that provides access to encrypted data stored on a computer readable medium, comprising:

means for securely booting the computer, comprising;

a Hardware Security Module (HSM);

a component that performs a trusted measurement of at least one boot component and submits a trusted measurement value to the HSM;

wherein said HSM compares said trusted measurement value to an HSM sealed value to authenticate said at least one boot component, and wherein said HSM unseals at least one secret when said at least one boot component is authentic;

means for decrypting a subsequent boot component using said at least one secret;

means for disabling said at least one secret comprising means for resetting said HSM sealed value to disable said at least one secret.

2. The computer of claim 1, wherein said encrypted data stored on a computer readable medium is a subset of the data that may be accessed by the computer.

3. The computer of claim 1, wherein the at least one secret is a secret needed by the means for securely booting the computer to successfully boot the computer.

4. The computer of claim 1, wherein said means for disabling comprises means for altering said at least one boot component to disable said at least one secret.

5. A computer readable storage medium bearing instructions for disabling access to at least one secret for booting an operating system that provides access to encrypted data stored on a computer readable medium, comprising:

instructions for securely booting the computer, comprising instructions for performing a trusted measurement of at least one boot component and submitting a trusted measurement value to a Hardware Security Module (HSM);

instructions for receiving a secret from said HSM, wherein said HSM compares said trusted measurement value to an HSM sealed value to authenticate said at least one boot component, then unseals said secret;

instructions for decrypting a subsequent boot component using said at least one secret;

instructions for disabling said at least one secret comprising instructions for resetting said HSM sealed value to disable said at least one secret.

6. The computer readable storage medium of claim 5, wherein said encrypted data stored on a computer readable medium is a subset of the data that may be accessed by the computer.

7. The computer readable storage medium of claim 5, wherein said instructions for disabling comprise instructions for altering said at least one boot component to disable said at least one secret.

8. A method for disabling access to at least one secret for booting an operating system that provides access to encrypted data stored on a computer readable medium, comprising:

in a computer equipped with a Hardware Security Module and instructions for securely booting the computer, wherein said instructions for securely booting comprise instructions for performing a trusted measurement of at least one boot component, submitting a trusted measurement value to said HSM, receiving at least one secret from said HSM and decrypting a subsequent boot component using said at least one secret;

decrypting said subsequent boot component;

initiating a process for locating and disabling said at least one secret; and

disabling said at least one secret, wherein disabling comprises resetting said HSM sealed value to disable said at least one secret.

9. The method of claim 8, wherein the at least one secret is a secret needed to successfully boot the computer.

10. The method of claim 8, wherein disabling comprises altering said at least one boot component to disable said at least one secret.