Methods and systems of protecting digital content

• US 20050273862A1
• Filed: 07/28/2005
• Published: 12/08/2005
• Est. Priority Date: 08/13/1999
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Benaloh, Josh D., Yuval, Gideon A., Rosen, Andrew D.
• Granted Patent: US 7,549,063 B2
• Time in Patent Office: Days
• US Class Current: 726/26
• CPC Class Codes: G06F 21/107 License processing; Key processing
• CPC Class Codes: G06F 21/16 Program or content traceability, e.g. by watermarking
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/606 Traitor tracing
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates

Abstract

Methods and systems are described that enable protection of digital content, such as movies and the like, by making pirated copies traceable back to a unique decryption key that was utilized to decrypt the originally encrypted content. The innovative advancements do not rely on post-distribution watermarking or fingerprinting techniques, and yet intrinsically link any unauthorized copies back to a unique cryptographic key or key collection that was used when the genuine copy was reproduced. In one embodiment, digital content is provided and comprises multiple partition sets, with each partition set comprising a first partition and at least one different version of the first partition. Each partition of each partition set is uniquely marked and encrypted with a different key. Individual unique key collections are then defined to contain, for each partition set, one key that was used to encrypt a partition from the partition set and no two key collections are identical. This means that each key collection can decrypt one unique version of the digital content. This unique version of the digital content is thus inextricably tied to the key collection that was utilized to decrypt the content. Each key collection is then encrypted with a different public key associated with one of multiple content players on which the digital content is to be played. Thus, each content player is inextricably associated with one key collection, and each key collection is inextricably associated with a unique version of the digital content. The digital content and one or more key collections can then be provided to the content players. When a content player decrypts its associated key collection and uses the key collection to decrypt the digital content, the version of the digital content that is decrypted points directly to the specific content-player that was authorized to decrypt it with that key collection.

Claims

1. A method of protecting digital content comprising:

partitioning digital content into multiple partitions;

making at least one copy of each of the multiple partitions to define multiple partition sets, each set containing one partition and at least one copy of the one partition;

uniquely marking each partition of a partition set; and

encrypting each partition of a partition set with a different key.

2. The method of claim 1, wherein the digital content comprises music.

3. The method of claim 1, wherein the digital content comprises a movie.

4. The method of claim 3, wherein the partitioning comprises partitioning the movie'"'"'s audio stream.

5. The method of claim 3, wherein the partitioning comprises partitioning the movie'"'"'s video stream.

6. The method of claim 1, wherein the acts of partitioning the digital content, making at least one copy of each partition, and uniquely marking each partition are accomplished at the same time.

7. The method of claim 1, wherein said uniquely marking comprises uniquely marking all of the partitions.

8. The method of claim 1, wherein said act of uniquely marking is not dependent on any particular marking technology.

9. The method of claim 1, wherein said act of uniquely marking is not dependent on any particular fingerprinting or watermarking technology.

10. One or more computer-readable media comprising computer-readable instructions thereon which, when executed by a computer, cause the computer to:

partition digital content into multiple partitions;

make at least one copy of each of the multiple partitions to define multiple partition sets, each set containing one partition and at least one copy of the one partition;

uniquely mark each partition of a partition set;

encrypt each partition of a partition set with a different key;

define multiple key collections each of which comprising a plurality of keys that were used to encrypt the partitions, each key collection containing one and only one key for each partition set, no two key collections being identical;

associate each key collection with a corresponding content player on which the digital content is to be played;

encrypt each key collection with a different public key of different public/private key pairs, each key pair being associated with a different content player that contains a private key that corresponds to a public key that was used to encrypt a key collection; and

provide the digital content, including all of the encrypted partitions, and one or more encrypted key collections onto one or more readable media for use by the content players.

11. The computer-readable media of claim 10, wherein the instructions cause all of the encrypted key collections to be provided onto one or more readable media for use by the content players.

12. The computer-readable media of claim 10, wherein the instructions cause all of the encrypted key collections to be provided onto multiple readable media for use by the content players, each readable media for use by the content players containing identical content.

13. The computer-readable media of claim 10, wherein the content players comprise in-flight DVD players.

14. A method of protecting digital content comprising:

providing digital content; and

processing the digital content sufficiently so that at least portions of the digital content are marked and encrypted such that when the portions are decrypted to provide the digital content in an unencrypted form, the decrypted digital content carries marks that indicate the key or keys that were used to decrypt it to provide the unencrypted digital content.

15. The method of claim 14, wherein the digital content comprises a movie.

16. The method of claim 15, wherein the marked portions of the digital content comprise audio portions of the movie.

17. The method of claim 15, wherein the marked portions of the digital content comprise video portions of the movie.

18. The method of claim 15, wherein the marked portions of the digital content comprise one or more of the audio and video portions of the movie.