System and method for secure storage of data using a key

• US 20050289067A1
• Filed: 08/19/2005
• Published: 12/29/2005
• Est. Priority Date: 10/26/1998
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: De Treville, John D., England, Paul, Lampson, Butler W.
• Application Number:
  US11/207,917
• Publication Number:
  US 20050289067A1
• Time in Patent Office: Days
• US Class Current: 705/51
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: G06F 2221/2113 Multi-level security, e.g. mandatory access control
• CPC Class Codes: G06F 9/4406 Loading of operating system
• CPC Class Codes: G06F 9/468 Specific access rights for resources, e.g. using capability register
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/166 at the transport layer

Abstract

In one aspect, a data structure to be encrypted is received in a device, the data structure including content along with a statement of conditions under which the content may be decrypted. The data structure is encrypted using a symmetric key of a processor of the device. In another aspect, a data structure is decrypted using a processor symmetric key. A statement of conditions under which content in the data structure can be decrypted is obtained, and testing is performed as to whether the conditions are satisfied. The decrypted content is returned only if the conditions are satisfied.

Claims

1. A method comprising:

receiving a data structure to be encrypted, wherein the data structure includes content along with a statement of conditions under which the content may be decrypted, wherein the statement of conditions comprises an operating system identity that an operating system executing on the device must have in order for the content to be decrypted; and

encrypting the content using a key.

2. A method as recited in claim 1, wherein the key comprises a symmetric key.

3. A method as recited in claim 1, wherein the key comprises a symmetric key of a processor of the device.

4. A method as recited in claim 1, wherein the operating system identity is maintained in a software identity register (SIR).

5. A method as recited in claim 1, wherein the operating system identity is identified in a signed certificate from an operating system vendor.

6. A method as recited in claim 1, wherein the operating system identity is for an operating system that is different than an operating system executing when the content to be encrypted is received.

7. A method as recited in claim 1, wherein encrypting the content comprises encrypting the data structure.

8. A system comprising:

means for obtaining a block of data to be encrypted, a current operating system identity, and a target operating system identity; and

means for invoking a seal operation to have the block of data encrypted by a processor of the system using a symmetric key of the processor.

9. A system as recited in claim 8, further comprising means for invoking the seal operation so that only an operating system having the target operating system identity can decrypt the encrypted block of data.

10. A system comprising:

means for invoking an unseal operation in order to have a data block decrypted using a key; and

means for receiving, in response to invoking the unseal operation, the decrypted data block only if conditions under which content in the data block can be decrypted are satisfied.

11. A system as recited in claim 10, wherein the key comprises a symmetric key.

12. A system as recited in claim 10, wherein the key comprises a symmetric key of a processor of the device.

13. A system as recited in claim 10, wherein the conditions comprise an operating system identity that an operating system invoking the unseal operation must have in order for the content to be decrypted.

14. A system as recited in claim 13, wherein the operating system identity of the operating system invoking the unseal operation is different than an operating system identity of an operating system that previously had the data block encrypted.

15. A system as recited in claim 10, further comprising means for receiving, in response to invoking the unseal operation, an error indication if the conditions are not satisfied.