Digital rights management in a mobile communications environment

Abstract

The invention provides a method, system, and computer program product to control the access, copying, and/or transfer of a digital asset by mobile, wireless devices using a digital voucher. The digital voucher references a primary content that contains all of the expression for that particular asset and a secondary content that contains information that can be distilled out as a preview. The information in the primary content can be limited to a specified duration or a specific number of viewings. The author, owner, or possessor of the digital asset specifies the terms and conditions for distribution of the digital asset. The digital voucher authorizes the mobile, wireless device to access a specified primary or secondary content that may be located elsewhere in the network. The mobile, wireless device can download a copy of portions or all of the content depending on the terms specified in the voucher.

1 - 73 . (Canceled)  
     
     
         74 . A method for distribution of a content item by sharing access to the content item comprising: 
 encrypting the content item with a first encryption key;    encrypting the first encryption key with at least one second encryption key to create at least one encrypted first encryption key;    creating a voucher for expressing usage rights associated with the content item;    storing said at least one encrypted first encryption key in the voucher;    associating the voucher with the content item, wherein the content item can be accessed by a device having at least one decryption key for decrypting at least one of said at least one encrypted first encryption key.    
     
     
         75 . The method of  claim 74 , wherein the first encryption key is randomly chosen.  
     
     
         76 . The method of  claim 74 , wherein said at least one second encryption key is related to a device identifier of the device.  
     
     
         77 . The method of  claim 74 , wherein said at least one second encryption key is related to a user identifier associated with the device.  
     
     
         78 . The method of  claim 74 , wherein said at least one second encryption key is related to a media identifier carrying the content.  
     
     
         79 . The method of  claim 74 , wherein said at least one second encryption key is a public key of the device.  
     
     
         80 . The method of  claim 74 , wherein said at least one second encryption key is a public key related to a user of the device.  
     
     
         81 . The method of  claim 74 , wherein said at least one second encryption key is a public key associated with the media carrying the content.  
     
     
         82 . The method of  claim 74 , wherein the content item is stored on a data carrying media.  
     
     
         83 . The method of  claim 74 , wherein the device is a rendering device.  
     
     
         84 . The method of  claim 74 , wherein the device is a storing device.  
     
     
         85 . A device for rendering a content item comprising: 
 means for encrypting the content item with a first encryption key;    means for encrypting the first encrypting key with at least one second encryption key to create at least one encrypted first encryption key;    means for associating said at least one encrypted first encryption key with the content item;    means for receiving the content item and said at least one encrypted first encryption key;    means for storing the content item;    means for storing said at least one encrypted first encryption key;    means for storing at least one decryption key for decrypting said at least one encrypted first encryption key;    means for decrypting said at least one encrypted first encryption key with said at least one decryption key;    means for decrypting the content item with the decrypted first encryption key;    means for rendering the decrypted content item.    
     
     
         86 . The device of  claim 85 , further comprising: 
 means for selecting one of the stored decryption keys.    
     
     
         87 . The device of  claim 85 , wherein at least one of said at least one second encryption key is a public key of the rendering device, and wherein the stored decryption key is a corresponding private key of the rendering device.  
     
     
         88 . The device of  claim 85 , wherein said at least one second encryption key is related to a device identifier of the rendering device.  
     
     
         89 . The device of  claim 85 , wherein said at least one second encryption key is related to a user identifier associated with the rendering device.  
     
     
         90 . The device of  claim 85 , wherein said at least one second encryption key is related to a media identifier carrying the encrypted content.  
     
     
         91 . The device of  claim 85 , wherein said at least one encrypted first encryption key is stored in a voucher associated with the content item.  
     
     
         92 . A device for rendering an encrypted content item comprising: 
 means for receiving the encrypted content item and an encryption key associated with the encrypted content item;    means for storing the encrypted content item;    means for storing the encryption key associated with the encrypted content item;    means for storing at least one decryption key for decrypting the encryption key associated with the encrypted content item;    means for decrypting the encryption key associated with the encrypted content item with said at least one decryption key;    means for decrypting the content item with said decrypted content encryption key;    means for rendering the decrypted content.    
     
     
         93 . The device of  claim 92 , further comprising: 
 means for selecting said at least one decryption key.    
     
     
         94 . The device of  claim 92 , wherein said at least one decryption key includes a decryption key relating to a device identifier, a decryption key relating to a user identifier associated with the device, a decryption key relating to a media identifier carrying the content item, a private key associated with the device, a private key associated with the user of the device, or a private key associated with the media carrying the encrypted content.  
     
     
         95 . The device of  claim 94 , wherein said at least one decryption key are tried in sequence for decrypting the encrypted content encryption key.  
     
     
         96 - 142 . (Canceled)