Method of broadcasting multimedia content via distribution network

• US 7,912,218 B2
• Filed: 06/23/2004
• Issued: 03/22/2011
• Est. Priority Date: 06/23/2004
• Status: Active Grant

• Current Assignee: III Holdings 6, LLC (Intellectual Ventures LLC)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Gentric, Philippe
• Primary Examiner(s): Zia, Syed A.
• Application Number:
  US10/562,531
• Publication Number:
  US 20060156377A1
• Time in Patent Office: 2,463 Days
• Field of Search: None
• US Class Current: 380/232
• CPC Class Codes: H04N 21/26613 for generating or managing keys in general key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments
• 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
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

The invention proposes to divide a content to be transmitted via a network into a set of slices and to generate a set of files from this set of slices. The slices (or the files) are encrypted before downloading in such a way that the client cannot use the slice (or the file) before having acquired the associated decryption key. The invention thereby allows protecting a downloaded content on a slice-by-slice basis (or on a file-by-file basis) rather than protecting a downloaded content as a whole. The transmission (in download mode) between the server and the client is ruled by the HTTP protocol that is accepted by all firewalls and NAT. Consequently, the transmitted content is accessible for any client device that has access to the Web without restriction. Advantageously, the slices can be decoded independently of each other.

Claims

1. A system comprising at least:

a source that acquires a multimedia content];

an encoder that encodes said multimedia content;

a slicer that slices said encoded multimedia content into a plurality of slices, wherein each of the slices is decoded independently, and generates a file from each of the slices, said slicer implementing an encryption algorithm, such that the slice contained in the file cannot be used without a decryption key associated therewith];

a distribution network;

an access provider that provides a client device with an access to said distribution network;

a content server linked to said distribution network and downloading said encoded multimedia content on a file-by-file basis to said client device via said distribution network upon reception of a request from said client device; and

a key server linked to said distribution network that provides said client device with the at least one decryption key associated with the at least one downloaded file.

2. The system of claim 1, wherein the decryption key is provided to said client device upon successful downloading of the file associated with the decryption key.

8. The system of claim 1, wherein payment for said multimedia content is progressive, limited to only downloaded files of said multimedia content.

3. A content server having access to files generated by slicing an encoded multimedia content into a plurality of slices, wherein each of the slices is decoded independently and the files are generated from each of the slices by implementing an encryption algorithm such that the slice contained in a file cannot be used without a decryption key associated therewith, said content server having means for downloading said encoded multimedia content on a file-by-file basis to a client device upon reception of a request from said client device, and means for sending a notification to a key server upon successful downloading of a file to said client device so that said key server provides said client device with the decryption key associated with said file.

9. The content server of claim 3, wherein payment for said multimedia content is progressive, limited to only downloaded files of said multimedia content.

4. A content server having access to files generated by slicing an encoded multimedia content into a plurality of slices, wherein each of the slices is decoded independently and the files are generated from each of the slices by implementing an encryption algorithm such that the slice contained in a file cannot be used without a decryption key associated therewith, said content server having means for downloading said encoded multimedia content on a file-by-file basis to a client device upon reception of a request from said client device, wherein said downloading means comprise:

means for sending a document to said client device upon reception of said request, said document causing said client device to repetitively send a fetching request designating said encoded multimedia content;

means for selecting which file is to be downloaded upon reception of said fetching requests from said client device; and

means for downloading the selected file.

12. The content server of claim 4, wherein payment for said multimedia content is progressive, limited to only downloaded files of said multimedia content.

5. A client device having:

means for connection to a content server, said content server having access to files (generated by slicing an encoded multimedia content into a plurality of slices, wherein each of the slices is decoded independently and the files are generated from each of the slices by implementing an encryption algorithm, such that the slice contained in a file cannot be used without a decryption key associated therewith, said content server downloading said encoded multimedia content on a file-by-file basis;

means for repeatedly sending to said content server a request directed to said encoded multimedia content;

means for receiving one of said files in response to each request;

means for acquiring the decryption key associated with each file; and

means for decrypting and playing said files.

6. The client device of claim 5, further comprising:

means for sending a subsequent request before ending playback of a current file.

10. The client device of claim 5, wherein payment for said multimedia content is progressive, limited to only downloaded files of said multimedia content.

7. A method of transmitting an encoded multimedia content to a client device, said method comprising the steps of:

encoding a multimedia content;

slicing said encoded multimedia content into a plurality of slices, wherein each of the slices is decoded independently and a file is generated from each of the slices by an encryption step, such that the slice contained in a file cannot be used without a decryption key associated therewith; and

downloading said encoded multimedia content on a file-by-file basis to said client device via said distribution network upon reception of a request from said client device.

11. The method of claim 7, wherein payment for said multimedia content is progressive, limited to only downloaded files of said multimedia content.