Systems and methods for distributing content using a common set of encryption keys

• US 10,856,020 B2
• Filed: 05/16/2019
• Issued: 12/01/2020
• Est. Priority Date: 09/01/2011
• Status: Active Grant

• Current Assignee: DivX, LLC (f/k/a DivX CF Holdings LLC) (SoftBank Group Corp.)
• Original Assignee: DivX, LLC (f/k/a DivX CF Holdings LLC) (SoftBank Group Corp.)
• Inventors: Kiefer, Michael George, Grab, Eric William, Braness, Jason
• Primary Examiner(s): Getachew, Abiy
• Application Number:
  US16/414,649
• Publication Number:
  US 20190342587A1
• Time in Patent Office: 565 Days
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/0819 Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) network architectures or network communication protocols for key distribution in a packet data network H04L63/062
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4627 Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/6334 for authorisation, e.g. by transmitting a key wireless communications network key management H04W12/04; wireless communications network access security H04W12/08
• CPC Class Codes: H04N 21/64715 Protecting content from unauthorized alteration within the network verifying the information received for network security in communication control or processing H04L63/12; integrity in wireless network security H04W12/10

Abstract

Systems and methods for performing adaptive bitrate streaming using alternative streams of protected content in accordance with embodiments of the invention are described. One embodiment of the invention includes a processor, and memory containing a client application. In addition, the client application configures the processor to: request a top level index file identifying a plurality of alternative streams of protected content, where each of the alternative streams of protected content are encrypted using common cryptographic information; obtain the common cryptographic information; request portions of content from at least the plurality of alternative streams of protected content; access the protected content using the common cryptographic information; and playback the content.

Claims

1. A content distribution system, comprising:

at least one content distribution server; and

a source encoder comprising a set of one or more processors and a memory containing an encoding application, wherein the encoding application configures the set of processors to encode source content as a plurality of alternative streams each having a different bitrate by performing the steps of;

identifying a plurality of sections for the source content;

identifying a common set of keys for encrypting corresponding portions of the source content across a plurality of different encodings;

encoding a first section and a second section of the plurality of sections to produce a plurality of encodings of the first section and a plurality of encodings of the second section for each of the plurality of alternative streams, wherein the plurality of encodings of the first section and the plurality of encodings of the second section each comprises encodings at a plurality of different bitrates;

partially encrypting at least one encoded frame from each encoding of the plurality of encodings of the first section using a first key of the common set of keys so that each partially encrypted frame contains encrypted portions and unencrypted portions of data;

partially encrypting at least one encoded frame from each encoding of the plurality of encodings of the second section using a second key of the common set of keys so that each partially encrypted frame contains encrypted portions and unencrypted portions;

storing the encrypted plurality of encodings of the first section and the encrypted plurality of encodings of the second section on a set of servers that form part of a content distribution system; and

storing a reference to the common set of keys on the at least one content distribution server.

2. The content distribution system of claim 1, wherein the source encoder is further configured to perform the step of storing encryption information that identifies an encrypted portion of at least one partially encrypted encoded frame.

3. The content distribution system of claim 2, wherein the encryption information comprises at least one of a reference to the start of an encrypted block of data within the encoded frame and a size of the encrypted block of data.

4. The content distribution system of claim 2, wherein the encryption information comprises cryptographic information that can be utilized to access the encrypted portion of the at least one partially encoded frame.

5. The content distribution system of claim 4, wherein the cryptographic information comprises a reference to a particular key.

6. The content distribution system of claim 1, wherein the source encoder is further configured to perform the step of storing the common set of keys on the at least one content distribution server.

7. The content distribution system of claim 6, wherein storing the common set of keys on the at least one content distribution server comprises encrypting the common set of keys.

8. The content distribution system of claim 1, wherein the at least one content distribution server is configured to perform the steps of:

receiving a request for content from a client device, where the requested content comprises one of the plurality of alternative streams of protected video;

receiving a request for cryptographic information from the client device, where the cryptographic information contains the common set of keys;

providing the requested content to the client device; and

providing the cryptographic information to the client device.

9. The content distribution system of claim 8, wherein the at least one content distribution server is configured to perform the steps of:

providing a top-level index to the client device, where the top-level index provides byte ranges for at least a portion of a container index of at least one encrypted encoding of the encrypted plurality of encodings; and

in response to a request for at least a portion of a container index from the client device, providing the at least a portion of the container index to the client device, wherein the at least a portion of the container index provides byte ranges for at least a portion the at least one encrypted encoding, wherein;

receiving a request for content comprises receiving a byte range request for a portion of the at least one encrypted encoding; and

providing the requested content comprises providing the requested byte range of the at least one encrypted encoding to the client device.

10. The content distribution system of claim 9, wherein the container index is generated during encoding and the top level index is generated based upon the received request.

11. A method for a set of one or more encoding servers of a content distribution system to encode source content as a plurality of alternative streams having different bitrates, the method comprising:

identifying a plurality of sections for the source content;

identifying a common set of keys for encrypting corresponding portions of the source content across a plurality of different encodings;

encoding a first section and a second section of the plurality of sections to produce a plurality of encodings of the first section and a plurality of encodings of the second section for each of the plurality of alternative streams, wherein the plurality of encodings of the first section and the plurality of encodings of the second section each comprises encodings at a plurality of different bitrates;

partially encrypting at least one encoded frame from each encoding of the plurality of encodings of the first section using a first key of the common set of keys so that each partially encrypted frame contains encrypted portions and unencrypted portions of data;

partially encrypting at least one encoded frame from each encoding of the plurality of encodings of the second section using a second key of the common set of keys so that each partially encrypted frame contains encrypted portions and unencrypted portions;

storing the encrypted plurality of encodings of the first section and the encrypted plurality of encodings of the second section on a set of servers that form part of a content distribution system; and

storing a reference to the common set of keys on the at least one content distribution server.

12. The method of claim 11 further comprising storing encryption information that identifies an encrypted portion of at least one partially encrypted encoded frame.

13. The method of claim 12, wherein the encryption information comprises at least one of a reference to the start of an encrypted block of data within the encoded frame and a size of the encrypted block of data.

14. The method of claim 12, wherein the encryption information comprises cryptographic information that can be utilized to access the encrypted portion of the at least one partially encoded frame.

15. The method of claim 14, wherein the cryptographic information comprises a reference to a particular key.

16. The method of claim 11 further comprising storing the common set of keys on the at least one content distribution server.

17. The method of claim 16, wherein storing the common set of keys on the at least one content distribution server comprises encrypting the common set of keys.

18. The method of claim 11 further comprising:

receiving a request for content from a client device, where the requested content identifies one of the plurality of alternative streams of protected video;

receiving a request for cryptographic information from the client device, where the cryptographic information contains the common set of keys;

providing the requested content to the client device; and

providing the cryptographic information to the client device.

19. The method of claim 18 further comprising:

providing a top-level index to the client device, where the top-level index provides byte ranges for at least a portion of a container index of at least one encrypted encoding of the encrypted plurality of encodings; and

in response to a request for at least a portion of a container index from the client device, providing the at least a portion of the container index to the client device, wherein the at least a portion of the container index provides byte ranges for at least a portion the at least one encrypted encoding, wherein;

receiving a request for content comprises receiving a byte range request for a portion of the at least one encrypted encoding; and

providing the requested content comprises providing the requested byte range of the at least one encrypted encoding to the client device.

20. The method of claim 19, wherein the container index is generated during encoding and the top level index is generated based upon the received request.