Method and system to uniquely associate multicast content with each of multiple recipients

Abstract

Methods and systems are disclosed in which contact can be safely distributed and protected in a manner that is viable in terms of bandwidth economy and ensures that clients can be identified by the content received. Copies of encrypted content can be provided such that unique watermarks can be added to the copies. Content can also be both watermarked uniquely for multiple clients and multicasted to the clients. As such, content can be distributed using the bandwidth efficiency of multicasting while providing reliable content protection and watermarking.

1 . A method comprising: 
 obtaining a copy of a content section with a first watermark;    obtaining a copy of a content section with a second watermark; and    providing a copy of the content to a client of a plurality of clients by combining, in a combination that is unique to the client, the copy of the content section with the first watermark, the copy of the content section with the second watermark, and a neutral content section.    
   
   
       2 . The method of  claim 1 , wherein the first watermark includes “0s” and the second watermark includes “1s.” 
   
   
       3 . The method of  claim 1 , further comprising: 
 distributing uniquely combined content sections to one or more clients on a network.    
   
   
       4 . The method of  claim 1 , further comprising: 
 encrypting the unique combination of content sections.    
   
   
       5 . The method of  claim 1 , further comprising: 
 scrambling the unique combination of content sections.    
   
   
       6 . The method of  claim 1 , wherein the first and second watermark each include one or more unique identifiers.  
   
   
       7 . A server comprising: 
 a module    to combine parts of a first copy of the content with the first watermark and parts of a second copy of the content with the second watermark in a manner unique for an individual client, and    to provide a plurality of copies of the content, each having a unique combination of sections with the first watermark and sections with the second watermark.    
   
   
       8 . The server of  claim 7 , wherein the first watermark includes “0s” and the second watermark includes “1s.” 
   
   
       9 . The server of  claim 7 , wherein the server is to distribute the combined parts to one or more clients on a network.  
   
   
       10 . The server of  claim 7 , wherein the server includes a media server module to provide content.  
   
   
       11 . The server of  claim 7 , wherein the server includes a storage device to store content.  
   
   
       12 . The server of  claim 7 , wherein the module is to receive a neutral copy of the content and to combine parts of the neutral copy, parts of the first copy with the first watermark, and parts of the second copy with the second watermark in a manner unique for an individual client.  
   
   
       13 . A computing system comprising: 
 means for receiving content from a content source;    means for combining parts of a first copy of the content with the first watermark and parts of the second copy with the second watermark in a manner unique for an individual client; and    means for providing a plurality of the copies of the content, each having a unique combination of sections marked with the first watermark and sections marked with the second watermark.    
   
   
       14 . The computing system of  claim 13 , wherein the first watermark includes “0s” and the second watermark includes “1s.” 
   
   
       15 . The computing system of  claim 13 , further comprising: 
 means for distributing the combined parts to one or more clients on a network.    
   
   
       16 . The computing system of  claim 13 , further comprising: 
 means for scrambling a neutral part of the content; and    means for combining parts of neutral copy, parts of the copy with the first watermark, and parts of the copy with the second watermark in a manner unique for an individual client.    
   
   
       17 . A machine-readable medium providing instructions, which if executed by a processor, causes the processor to perform an operation comprising: 
 scrambling a copy of at least one part of content having a first watermark;    scrambling a copy of at least one part of content having a second watermark; and    providing scrambled copies for each of a plurality of clients by combining parts of the scrambled copy with the first watermark and parts of the scrambled copy with the second watermark in a manner unique for an individual client, such that the scrambled copies have a unique combination of sections marked with the first watermark and sections marked with the second watermark.    
   
   
       18 . A digital processing system comprising: 
 a first module to provide content having a plurality of double parts, a first part watermarked with a first identifier and a second part watermarked with a second identifier;    a second module coupled to the first module, the second module to scramble the content with a first key, to scramble the first part watermarked with the first identifier with a second key, and to scramble the second part watermarked with the second identifier with a third key; and    a key management module to manage the keys as to allow one or more clients to unscramble the scramble content with a combination of scrambled first and second parts watermarked with the first identifier and second identifier, respectively, unique to each client.    
   
   
       19 . The digital processing system of  claim 18 , wherein the first identifier includes “0s” and the second identifier includes “1s.” 
   
   
       20 . The digital processing system of  claim 18 , wherein the second module is to provide entitlement control messages (ECMs) using the first key, second key, and third key, wherein the second and third key are alternated to obtain a unique combinations of “0s” and “1s” unique to each client.  
   
   
       21 . The digital processing system of  claim 18 , wherein the system includes a storage device to store a client identification and a corresponding unique combination of watermarked copies for the client.  
   
   
       22 . A key management module comprising:  
     a first component to manage a plurality of keys as to allow one or more clients to decrypt encrypted content with a combination of encrypted first and second parts watermarked with a first identifier and second identifier, respectively, unique to each client; and  
     a second component to communicate key management information to at least one other module.  
   
   
       23 . A machine-readable medium providing instructions, which if executed by a processor, causes the processor to perform an operation comprising: 
 watermarking redundant parts of content with one or more unique watermarks;    encrypting the watermarked redundant parts using a unique key for each unique watermark; and    combining encrypted parts and nonencrypted parts of the content into a single stream of data.    
   
   
       24 . A method of distributing content, the method comprising: 
 watermarking first and second duplicates of a content portion with first and second signatures respectively;    encrypting each of the first and second duplicates of the content portion with at least first and second keys respectively;    supplying both the first and second duplicates of the content portion to first and second users; and    supplying at least the first key to the first user and the second key to the second user, so that the first user is enabled to decrypt the first duplicate of the content portion watermarked with the first signature, and so that the second user is enabled to decrypt the second duplicate of the content portion watermarked with the signature.    
   
   
       25 . The method of  claim 24 , wherein the content includes text, audio, or video content.  
   
   
       26 . The method of  claim 24 , wherein the supplying of the first and second duplicates and keys includes supplying the first and second duplicates and keys via a network.  
   
   
       27 . An apparatus comprising: 
 watermarking means for watermarking first and second duplicates of a content portion with first and second signatures respectively;    encrypting means for encrypting each of the first and second duplicates of the content portion with at least first and second keys respectively;    supplying means for supplying both the first and second duplicates of the content portion to first and second users; and    supplying means for supplying at least the first key to the first user and the second key to the second user, so that the first user is enabled to decrypt the first duplicate of the content portion watermarked with the first signature, and so that the second user is enabled to decrypt the second duplicate of the content portion watermarked with the second signature.    
   
   
       28 . The apparatus of  claim 27 , wherein the content includes text, audio, or video content.  
   
   
       29 . The apparatus of  claim 27 , wherein the supplying means for the first and second duplicates and keys include supplying means for supplying the first and second duplicates and keys via a network.  
   
   
       30 . A machine-readable medium providing instructions, which if executed by a processor, causes the processor to perform an operation comprising: 
 prior to communication of an encrypted copy of content, 
 watermarking first and second duplicates of a content portion with first and second signatures respectively;  
 encrypting each of the first and second duplicates of the content portion with at least first and second keys respectively;  
   after the watermarking and the encrypting, 
 supplying both the first and second duplicates of the content portion to first and second users; and  
 supplying at least the first key to the first user and the second key to the second user, so that the first user is enabled to decrypt the first duplicate of the content portion watermarked with the first signature, and so that the second user is enabled to decrypt the second duplicate of the content portion watermarked with the second signature.  
   
   
   
       31 . A method of distributing content, the method comprising: 
 watermarking multiple sets of duplicated content portions with multiple sets of signatures, each signature of each set being unique to a specific duplicated content portion;    encrypting each duplicated content portion within each set with a respective key of a plurality of keys;    supplying the multiple sets of duplicated content portions to multiple users; and    supplying a unique set of keys, selected from the plurality of keys, to each of the multiple users so that each of the multiple users is enabled to decrypt the multiple sets of duplicated content portions to generate content embodying a unique sequence of signatures.    
   
   
       32 . The method of  claim 31 , wherein the supplying of the multiple sets of duplicated content portions includes multicasting the multiple sets of duplicated content portions to the multiple users on an Internet network.  
   
   
       33 . The method of  claim 32 , wherein the supplying of the unique sets of keys to each of the multiple users includes unicasting the unique set of keys to each of the multiple users on the Internet network.  
   
   
       34 . The method of  claim 31 , wherein the content portions include text, audio, or video content portions.  
   
   
       35 . An apparatus comprising: 
 prior to communication of an encrypted copy of content 
 watermarking means for watermarking multiple sets of duplicated content portions with multiple sets of signatures, each signature of each set being unique to a specific duplicated content portion;  
 encrypting means for encrypting each duplicated content portion within each set with a respective key of a plurality of keys;  
 supplying means for supplying the multiple sets of duplicated content portions to multiple users after the watermarking and the encrypting; and  
   supplying means for supplying a unique set of keys, selected from the plurality of keys, to each of the multiple users so that each of the multiple users is enabled to decrypt the multiple sets of duplicated content portions to generate content embodying a unique sequence of signatures.    
   
   
       36 . The apparatus of  claim 35 , wherein the supplying means for supplying of the multiple sets of duplicated content portions includes multicasting means for multicasting the multiple sets of duplicated content portions to the multiple users on an Internet network.  
   
   
       37 . The apparatus of  claim 35 , wherein the supplying means for supplying of the unique sets of keys to each of the multiple users includes unicasting means for unicasting the unique set of keys to each of the multiple users on the Internet network.  
   
   
       38 . The apparatus of  claim 35 , wherein the content portions include text, audio. or video content portions.  
   
   
       39 . A machine-readable medium providing instructions, which if executed by a processors, causes the processor to perform an operation comprising: 
 prior to communication of an encrypted copy of content, 
 watermarking multiple sets of duplicated content portions with multiple sets of signatures, each signature of each set being unique to a specific duplicated content portion;  
 encrypting each duplicated content portion within each set with a respective key of a plurality of keys;  
 supplying the multiple sets of duplicated content portions to multiple users after the watermarking and encrypting; and  
 supplying a unique set of keys, selected from the plurality of keys, to each of the multiple users so that each of the multiple users is enabled to decrypt the multiple sets of duplicated content portions to generate content embodying a unique sequence of signatures.