Partial encryption of stream-formatted media

• US 20040028227A1
• Filed: 08/08/2002
• Published: 02/12/2004
• Est. Priority Date: 08/08/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yu, Hong Heather
• Granted Patent: US 7,167,560 B2
• Time in Patent Office: Days
• US Class Current: 380/201
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0478 applying multiple layers of encryption, e.g. nested tunnels or encrypting the content with a first key and then with at least a second key cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04N 21/234327 by decomposing into layers, e.g. base layer and one or more enhancement layers
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

A method of partially encrypting streaming media according to an embodiment of the invention comprises: receiving media in a streaming-media format; partitioning the stream-formatted media into cloak data and non-cloak data; and encrypting the cloak data such that less than all of the stream-formatted media is encrypted.

Claims

1. A method of partially encrypting streaming media, the method comprising:

receiving media in a streaming format;

partitioning the stream-formatted media into cloak data and non-cloak data; and

encrypting the cloak data such that less than all of said stream-formatted media is encrypted.

2. The method of claim 1, further comprising:

compressing said stream-formatted media, wherein the partial encryption operates upon the compressed media.

3. The method of claim 1, wherein the partition is of a one-dimensional partition.

4. The method of claim 3, wherein the dimension of partition is one of the time dimension, the spatial dimension and the bit plane dimension.

5. The method of claim 1, wherein the partition is a multidimensional partition such that there are at least two of a time dimension partition, a spatial dimension partition and a bit plane dimension partition.

6. The method of claim 5, wherein the partition is of a two dimensional partition such that a first one of the dimensions is the time dimension and a second one of the dimensions is a spatial dimension.

7. The method of claim 1, further comprising:

scalably encoding the non-cloak data and the encrypted cloak data.

8. The method of claim 7, wherein the scalable encodation is either layer scalable or bit plane scalable, and wherein the layer scalable encodation includes a core layer and at least one enhancement layer.

9. The method of claim 8, wherein the layers of said layer scalable encodation represent a partition in one of the temporal dimension, the spatial dimension and the bit plane dimension.

10. The method of claim 8, wherein the layers of said layer scalable encodation represent a partition in the bit plane dimension;

wherein said core layer represents the more significant bit planes M-1, M-2, . . . M-K out of a total of M bit planes corresponding to an M-bit word architecture representing a pixel value; and

wherein said enhancement layer represents the less significant bit planes M-K-1, M-K-2, . . . 1, 0;

and

wherein , where K<

M, and both K and M are positive integers.

11. The method of claim 10, wherein said enhancement layer is encrypted.

12. The method of claim 1, wherein said step of partitioning selects a portion of said stream-formatted media irrespective of relative content importance.

13. The method of claim 12, wherein said stream-formatted media is divided into blocks, and wherein the cloak data represents a predetermined subset of said blocks.

14. The method of claim 1, wherein said step of partitioning selects a portion of said stream-formatted media based upon relative content importance of different portions of the media.

15. The method of claim 14, wherein said step of partitioning selects for encryption said stream-formatted media whose content is of relatively greater importance.

16. The method of claim 14, wherein, for the circumstance in which stream-formatted media is formed based at least in part upon the Discrete Cosine Transformation (“

DCT”

) or the modified DCT (“

MDCT”

), said cloak data corresponds to the lower frequency coefficients of said DCT or MDCT.

17. The method of claim 14, wherein, for the circumstance in which the partition is at least partly in the spatial dimension, said cloak data corresponds to a portion of the media representing an amount of motion that exceeds a predetermined level.

18. The method of claim 14, wherein

the partition is a bit plane partition;

and

said cloak data corresponds to a subset of the bit planes.

19. The method of claim 18, wherein said cloak data corresponds to the N most significant bit planes out of a total of M bit planes corresponding to an M-bit word architecture representing a pixel value, where N<

M, and both N and M are positive integers.

25. A computer-readable medium having code portions embodied thereon that, when read by a processor, cause said processor to perform the method of claim 1.

20. An apparatus for partially encrypting streaming media, the apparatus comprising:

means for receiving media to be streamed and for encoding said media into a streaming-media format;

partition means for partitioning the stream-formatted media into cloak data and non-cloak data; and

encryption means for encrypting the cloak data such that less than all of said stream-formatted media is encrypted.

21. The apparatus of claim 20, wherein said cloak data corresponds to a portion of the media whose content is of relatively greater importance.

22. The apparatus of claim 21, wherein, for the circumstance in which stream-formatted media is formed based at least in part upon the Discrete Cosine Transformation (“

DCT”

) or the modified DCT (“

MDCT”

), said cloak data corresponds to the lower frequency coefficients of said DCT or MDCT.

23. The method of claim 21, wherein the partition is at least in part in the spatial dimension, and said cloak data corresponds to a portion of the media representing an amount of motion that exceeds a predetermined level.

24. The method of claim 21, wherein

the partition is a bit plane partition;

and

said cloak data is a subset of the bit planes.