Content publication

• US 7,680,937 B2
• Filed: 06/27/2006
• Issued: 03/16/2010
• Est. Priority Date: 12/22/2005
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Weiss, Rebecca C., Hydrie, Aamer, Rodriguez Rodriguez, Pablo, Garcia-Mendoza, Armando, Klemets, Anders E., Miller, John, Gkantsidis, Christos
• Primary Examiner(s): Abdullahi; Salad
• Assistant Examiner(s): Hussain; Imad
• Application Number:
  US11/426,820
• Publication Number:
  US 20070150596A1
• Time in Patent Office: 1,358 Days
• Field of Search: 709/224, 709/226, 709/230
• US Class Current: 709/226
• 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 21/645 using a third party
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263

Abstract

Publishing content using a peer-to-peer content distribution system is described. A publisher is required to request authorization to publish from an authorization body. Resources such as tracker and seed nodes are allocated in a peer-to-peer content distribution system and pre-processing of content to be published is carried out. For example, a content description is generated for each item of content as well as a set of checksums or other items for validating blocks of content. Publication can be terminated in a variety of different ways. For example, by using expiry methods, by active revocation of publishers, authorization bodies, or individual items of content.

Claims

1. A method implemented by a processor on a first computer executing instructions stored in machine readable form on a storage media, the method comprising:

receiving, by the first computer, a content description of content to be distributed using a peer-to-peer content distribution system, wherein the content description includes information regarding a certificate issued by an authorization body to authorize a publisher to distribute the content, wherein the content is divided into a plurality of blocks for distribution using the peer-to-peer distribution system;

receiving, by the first computer, a set of checksums for the content, the set of checksums comprising a plurality of series of checksums, wherein each series of the plurality of series of checksums includes at least one checksum generated for each block of the content, wherein the checksums are generated by using a known seed to generate a sequence of pseudo-random numbers, each of which is combined with a corresponding block of the content;

receiving, at the first computer, a request from a second computer for information relating to the content;

authenticating the second computer by the first computer, wherein the authenticating includes verifying an identity of the second computer;

providing a subset of the plurality of series of the checksums and the content description to the second computer following authentication of the second computer, wherein the second computer uses the subset of the plurality of series of checksums to verify integrity of each of the blocks of the content;

receiving, at the first computer, a request from a third computer for information relating to the content; and

providing a different subset of the plurality of series of checksums to the third computer that includes at least one series of checksums that is different than the series of checksums provided to the second computer.

2. A method as claimed in claim 1, further comprising:

generating the series of checksums by combining each pseudorandom number with the corresponding block by combining the sequence of pseudorandom numbers with a sequence of bytes for each uncoded block to create a list of checksums comprising one checksums for each uncoded block of the content.

3. A method as claimed in claim 1, further comprising storing an identifier at the first computer identifying the subset of the plurality of the series of checksums provided to the second computer for ensuring that a same subset of the plurality of series of checksums is provided to the second computer in response to a second request for information relating to the content received from the second computer.

4. A method as claimed in claim 1, further comprising receiving, by the first computer, instructions on how the series of checksums are distributed to peer computers, the instructions including how many series of the plurality of series are distributed to the peer computers.

5. A method as claimed in claim 1, further comprising receiving at the first computer a location of at least one seed node containing at least some of the content.

6. A method as claimed in claim 1, wherein the content description comprises the certificate for securing the content to protect against unauthorized consumption.

7. A method as claimed in claim 1, wherein the set of checksums for the content is generated by the publisher using a numerical seed combined with the plurality of blocks of the content for determining each series of checksums of the plurality of series of checksums.

8. A method as claimed in claim 1, wherein the first computer receives a copy of a certificate revocation list for comparison with the certificate issued by the authorization body to authorize a publisher to distribute the content.

9. A method as claimed in claim 1, further comprising:

determining, by the first computer, from the content description, that the publisher is no longer authorized to distribute the content; and

ceasing, by the first computer, to distribute the content description and information regarding location of the content.

10. A method as claimed in claim 1, wherein the content description for the content includes information about the content and information about the publisher of that content that is used by the first computer and/or the second computer for determining that the publisher is authorized to distribute the content.

11. A method as claimed in claim 10, wherein the first computer uses an identifier of the second computer mapped using a specified function for determining one or more series of checksums that make up the subset of the plurality of series of checksums provided to the second computer to ensure that a same subset of the plurality of series of checksums is provided to the second computer in response to a second request for information relating to the content received from the second computer.

12. A method as claimed in claim 11, wherein the subset of the series of checksums received by the second computer is used to verify the integrity of the one or more blocks of the content by checking that a calculated checksum calculated by the second computer matches a particular checksum in the subset of the series of checksums received by the second computer from the first computer.

13. A system comprising:

a publishing computer including a storage medium containing instructions stored in a machine readable form adapted to be implemented by a processor on the publishing computer for;

receiving authorization to publish content using a peer-to-peer content distribution system, the authorization including a certificate issued by an authorization body to authorize the publishing computer to distribute the content, wherein the content is divided into a plurality of blocks for distribution using the peer-to-peer distribution system;

sending information about the content and the authorization to a tracker computer;

calculating a plurality of series of checksums for the content, wherein the series of checksums includes at least one checksum generated for each block of the content, wherein the checksums are generated using a sequence of pseudo-random numbers which are combined with corresponding blocks of content; and

sending the plurality of series of checksums to the tracker computer for distribution to peer computers for use by the peer computers in verifying integrity of the content following download, wherein the different peer computers receive different series of checksums.

14. A system as claimed in claim 13, wherein the publishing computer further implements:

sending at least some of the content to at least one seed computer, and

sending identification of the seed computer to the tracker computer with the information about the content and the authorization sent to the tracker computer.

15. A system as claimed in claim 13, wherein a certificate revocation list is distributed to the tracker computer for determining validity of the authorization of the publishing computer.

16. A system as claimed in claim 13 wherein the publishing computer implements:

sending instructions to the tracker computer on how the series of checksums are distributed to peer computers, the instructions including how many series of the plurality of series are distributed to the peer computers.

17. A method implemented by a processor on a first computer executing instructions stored in machine readable form on a storage media, the method comprising:

sending a request from the first computer to a second computer for obtaining information about content published using a peer-to-peer content distribution system, wherein the content is divided into a plurality of blocks for distribution using the peer-to-peer distribution system;

receiving the information about the content at the computer, the information about the content including an authorization issued to a publisher to publish the content, a location of the content, and a plurality of checksum values for verifying integrity of the content, wherein the checksum values are generated using a sequence of pseudo-random numbers which are combined with corresponding blocks of the content;

verifying the authorization of the publisher to publish the content;

downloading the plurality of blocks of the content to the first computer;

verifying integrity of each block of the content downloaded from the location using corresponding ones of the plurality of checksum values.

18. A method as claimed in claim 17 wherein the verifying the authorization of the publisher to publish the content comprises checking a certificate of the publisher against a certificate revocation list.

19. A method as claimed in claim 17 wherein, when one of the blocks fails verification of integrity, the first computer no longer accepts content from the location from which the block that failed verification was downloaded.

20. A method as claimed in claim 17, further comprising:

in addition to verifying integrity of each block downloaded to the first computer using the plurality of checksums, assembling the plurality of blocks downloaded to the first computer to form assembled content; and

verifying integrity of the assembled content by calculating a hash function for the assembled content and comparing the calculated hash function with a hash value received from the second computer.