Protecting decrypted compressed content and decrypted decompressed content at a digital rights management client

• US 20050271208A1
• Filed: 07/07/2005
• Published: 12/08/2005
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: England, Paul, Peinado, Marcus, Sankaranarayan, Mukund
• Granted Patent: US 7,080,410 B2
• Time in Patent Office: Days
• US Class Current: 380/269
• 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]

Abstract

Theft of decompressed digital content as the content is being rendered is prevented. A requested slow-down of the rendering of the content is detected. Transfers of relatively large amounts of data are detected. A re-compressor-based requested slow-down of the rendering of the content is detected. A re-compressor re-compressing the content is detected. In each situation, the detected activity is presumably initiated by a content thief attempting to steal the content. In each situation, the detected activity is responded to in a manner designed to frustrate the presumed attempt of the content thief to steal the content.

Claims

1-14. -14. (canceled)

15. A method of preventing theft of decompressed digital content as the content is being rendered, the method comprising:

detecting a re-compressor-based requested slow-down of the rendering of the content, wherein the detected requested slow-down is presumably initiated by a content thief attempting to steal and re-compress the content; and

responding to the detected requested slow-down in a manner designed to frustrate the presumed attempt of the content thief to steal and re-compress the content.

16. The method of claim 15 wherein detecting comprises sensing X consecutive SEEK or STEP operations.

18. The method of claim 15 wherein detecting comprises consulting all available clocks and determining therefrom if rendering is occurring at less than real-time speed.

19. The method of claim 15 wherein detecting comprises sensing excessive SEEK and GET_POS commands.

20. The method of claim 15 wherein responding comprises ignoring control operations such as SEEK and STEP for Y seconds.

21. The method of claim 20 wherein responding comprises ignoring control operations such as SEEK and STEP for 30 seconds.

22. The method of claim 15 wherein responding comprises performing a non-responsive action.

23. The method of claim 22 wherein responding comprises performing a non-responsive action selected from a group consisting of rendering at real-time speed, intentionally omitting rendering of frames, and stopping rendering.

24. The method of claim 15 wherein responding comprises providing requested data with a built-in error.

25. The method of claim 24 wherein responding comprises providing requested data with a built-in error which gets progressively worse.

17. (canceled)

26-43. -43. (canceled)

44. A computer-readable medium having computer-executable instructions thereon for preventing theft of decompressed digital content as the content is being rendered, the instructions being organized into modules including:

a first module for detecting a re-compressor-based requested slow-down of the rendering of the content, wherein the detected requested slow-down is presumably initiated by a content thief attempting to steal and re-compress the content; and

a second module for responding to the detected requested slow-down in a manner designed to frustrate the presumed attempt of the content thief to steal and re-compress the content.

45. The medium of claim 44 wherein the first module senses X consecutive SEEK or STEP operations.

47. The medium of claim 44 wherein the first module consults all available clocks and determining therefrom if rendering is occurring at less than real-time speed.

48. The medium of claim 44 wherein the first module senses excessive SEEK and GET_POS commands.

49. The medium of claim 44 wherein the second module ignores control operations such as SEEK and STEP for Y seconds.

50. The medium of claim 49 wherein the second module ignores control operations such as SEEK and STEP for 30 seconds.

51. The medium of claim 44 wherein the second module performs a non-responsive action.

52. The medium of claim 51 wherein the second module performs a non-responsive action selected from a group consisting of rendering at real-time speed, intentionally omitting rendering of frames, and stopping rendering.

53. The medium of claim 44 wherein the second module provides requested data with a built-in error.

54. The medium of claim 53 wherein the second module provides requested data with a built-in error which gets progressively worse.

46. (canceled)

55-58. -58. (canceled)