PATENT DOCUMENT

Publication Number: US-11727376-B2
Application Number: US-201916417470-A
Country: US
Kind Code: B2

Title: Use of media storage structure with multiple pieces of content in a content-distribution system

Abstract:
A method for distributing content. The method distributes a single media storage structure to a device (e.g., a computer, portable player, etc.). The media storage structure includes first and second pieces of encrypted content. Based on whether the device is allowed to access the first piece of content, the second piece of content, or both, the method provides the device with a set of keys for decrypting the pieces of the content that the device is able to access. The provided set of keys might include one or more keys for decrypting only one of the two encrypted pieces of content. Alternatively, it might include one or more keys for decrypting both encrypted pieces of content. For instance, the selected set of keys might include a first key for decrypting the first encrypted piece and a second key for decrypting the second encrypted piece.

Claims:
What is claimed is: 
     
       1. A digital rights management server device comprising:
 a memory; and 
 at least one processor configured to: 
 determining that a media storage structure has been transferred to a first device, the media storage structure storing a set of encrypted content pieces relating to a particular presentation, the set of encrypted content pieces comprising a first content piece of a first content type and second and third content pieces of a second content type that differs from the first content type; 
 determining that the media storage structure has been transferred to a second device; 
 providing to the first device a first key for decrypting the first content piece and a second key for decrypting the second content piece; and 
 providing to the second device the first key for decrypting the first content piece and a third key for decrypting the third content piece. 
 
     
     
       2. The device of  claim 1 , wherein the first content type comprises audio content and the second content type comprises video content. 
     
     
       3. The device of  claim 2 , wherein the particular presentation comprises a video program. 
     
     
       4. The device of  claim 3 , wherein the first content piece comprises an audio track for the video program. 
     
     
       5. The device of  claim 3 , wherein the second and third content pieces comprise two different video clips from different angles of the video program. 
     
     
       6. The device of  claim 3 , wherein the first device is configured to present the video program using the first content piece and the second content piece and the second device is configured to present the program using the first content piece and the third content piece. 
     
     
       7. The device of  claim 2 , wherein the second and third content pieces comprise two different videos corresponding to the first content piece. 
     
     
       8. The device of  claim 1 , wherein the digital rights management server device is part of a DRM management system that further includes a content distribution server. 
     
     
       9. A method comprising:
 determining, by a digital rights management server device, that a media storage structure has been transferred to a first device, the media storage structure storing a set of encrypted content pieces relating to a particular presentation, the set of encrypted content pieces comprising a first content piece of a first content type and second and third content pieces of a second content type that differs from the first content type; 
 determining, by a digital rights management server device, that the media storage structure has been transferred to a second device; 
 providing, by a digital rights management server device, to the first device a first key for decrypting the first content piece and a second key for decrypting the second content piece; and 
 providing, by a digital rights management server device, to the second device the first key for decrypting the first content piece and a third key for decrypting the third content piece. 
 
     
     
       10. The method of  claim 9 , wherein the first content type comprises video content and the second content type comprises audio content. 
     
     
       11. The method of  claim 10 , wherein the particular presentation comprises a video program. 
     
     
       12. The method of  claim 11 , wherein the second content piece comprises an audio track for the video program in a first language and the third content piece comprises an audio track for the video program in a second language. 
     
     
       13. The method of  claim 11 , further comprising transferring, by a first content distribution server, the media storage structure to the first device and transferring, by a second content distribution server, the media storage structure to the second device. 
     
     
       14. The method of  claim 13 , further comprising: receiving, by the first device, the media storage structure from the first content distribution server; and presenting, by the first device, the video program using the first content piece and the second content piece. 
     
     
       15. The method of  claim 14 , further comprising: receiving, by the second device, the media storage structure from the second content distribution server; and presenting, by the second device, the video program using the first content piece and the third content piece. 
     
     
       16. A non-transitory machine-readable medium comprising code that, when executed by one or more processors of a digital rights management server device, causes the one or more processors to perform operations comprising:
 determining that a media storage structure has been transferred to a first device, the media storage structure storing a set of encrypted content pieces relating to a particular presentation, the set of encrypted content pieces comprising a first content piece of a first content type and second and third content pieces of a second content type that differs from the first content type; 
 determining that the media storage structure has been transferred to a second device; 
 providing to the first device a first key for decrypting the first content piece and a second key for decrypting the second content piece; and 
 providing to the second device the first key for decrypting the first content piece and a third key for decrypting the third content piece. 
 
     
     
       17. The non-transitory machine-readable medium of  claim 16 , wherein the first content type comprises audio content and the second content type comprises video content. 
     
     
       18. The non-transitory machine-readable medium of  claim 16 , wherein the first content type comprises video content and the second content type comprises audio content.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 13/612,766, filed Sep. 12, 2012, which is a continuation of U.S. patent application Ser. No. 11/249,123, filed Oct. 11, 2005, now issued as U.S. Pat. No. 8,306,918, the disclosures of which are hereby incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the use of a single media storage structure with multiple pieces of content in a digital rights management system. 
     BACKGROUND OF THE INVENTION 
     The protection of digital content transferred between computers over a network is fundamentally important for many enterprises today. Enterprises attempt to secure this protection by implementing some form of Digital Rights Management (DRM) process. The DRM process often involves encrypting the piece of content (e.g., encrypting the binary form of the content) to restrict usage to those who have been granted a right to the content. 
     Cryptography is the traditional method of protecting data in transit across a network. In its typical application, cryptography protects communications between two mutually trusting parties from an attack on the data in transit. However, for many digital file transfer applications today (e.g., for the transfer of audio or video content), the paradigm has shifted, as a party that receives the content (i.e., the “receiving party”) might try to break the DRM encryption that the party that supplied the content (i.e., the “distributing party”) applied to the content. In addition, with the proliferation of network penetration attacks, a third party may obtain access to the receiving party&#39;s computer and thus to the protected content. 
     Some pieces of content that are distributed in existing DRM systems are related to one another. However, existing DRM system often do not allow content recipients to flexibly purchase or license a subset of the contents from a related set of DRM contents. For instance, one existing DRM system distributes certain songs along with their associated music videos. In distributing a song along with its associated music video, this DRM system rigidly requires a recipient either (1) to purchase both the song and its associated music video, or (2) to forego access to both the song and its associated music video. Therefore, there is a need in the art for a DRM system that flexibly allows content recipients to purchase or license a subset of the content from a related set of DRM contents. 
     SUMMARY OF THE INVENTION 
     Some embodiments of the invention provide a method for distributing content over a network. The method distributes a single media storage structure to a device (e.g., a computer, portable player, etc.) that connects to the network. The media storage structure includes first and second pieces of encrypted content. Based on whether the device is allowed to access the first piece of content, the second piece of content, or both, the method provides the device with a set of keys for decrypting the pieces of the content that the device is able to access. 
     The provided set of keys might include one or more keys for decrypting only one of the two encrypted pieces of content. Alternatively, it might include one or more keys for decrypting both encrypted pieces of content. For instance, the selected set of keys might include a first key for decrypting the first encrypted piece and a second key for decrypting the second encrypted piece. Based on the provided set of keys, the device can then decrypt and access either one of the two pieces of content in the media storage structure or both pieces of encrypted content in the media storage structure. 
     The media storage structure includes a first content section that stores the first piece of encrypted content, and a second content section that stores the second piece of encrypted content. In some embodiments, the media storage structure also includes first and second key sections respectively for storing first and second keys for decrypting the first and second pieces of encrypted content. The method of some embodiments distributes the media storage structure with the encrypted first and second content pieces from a computer that is separate from the computer or computers that distribute the first and second keys. In some embodiments, the device that receives the media storage structure inserts the first and second keys in the first and second key sections of the media storage structure. 
     One piece of encrypted content might be audio content (e.g., an audio track, a song, a sound track, etc.) related to a particular presentation (e.g., a music video, a film, etc.), while the other piece of encrypted content might be video content (e.g., a video track, a video clip, etc.) related to the particular presentation. Alternatively, both pieces of content can be video content (e.g., video clips from different angles of one or more scenes) or audio content (e.g., different versions or mixes of a song or different languages for the dialogue in a movie). In addition, content other than audio or video might be stored in the media storage structure. For instance, one piece of content might be audio or video content, while the other piece of content might be lyrics or dialogue associate with the audio or video content piece. 
     The method in some embodiments distributes a media storage structure that contains more than two pieces of content. For instance, in some cases, the media storage structure includes one piece of audio content and two pieces of video content, which can be two different video clips associated with the audio content (e.g., can be two different music videos that are associated with a song). 
     In some embodiments, the device (e.g., the computer) that receives the media storage structure transfers the media storage structure to another device (e.g., to a portable player). In this transfer, one of the pieces of content from the media storage structure might be removed in the transfer of the media storage structure to the other device (e.g., in the portable player). In some cases, content is removed from the media storage structure in order to reduce the consumption of resources on the other device. In other cases, content is removed from the media storage structure because the other device does not have rights to access this other content. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the invention are set forth in the appended claims. However, for purpose of explanation, several embodiments are set forth in the following figures. 
         FIG.  1    illustrates an example of such a media storage structure. 
         FIG.  2    illustrates an example where the selected set of keys includes a first key for decrypting the first encrypted piece of content and a second key for decrypting the second encrypted piece of content. 
         FIG.  3    illustrates another example of the media storage structure. 
         FIGS.  4 - 10    illustrate various examples of related pieces of content in a media storage structure of some embodiments. 
         FIG.  11    illustrates a content-distribution system of some embodiments. 
         FIG.  12    conceptually illustrates an example of one possible set of interactions between the computer, the DRM server, and the content-caching server. 
         FIG.  13    illustrates another example of a computer acquiring a media file. 
         FIG.  14    illustrates a computer&#39;s storage of the two keys that it receives in the example illustrated in  FIG.  11   . 
         FIG.  15    illustrates a computer&#39;s storage of the key that it receives in the example illustrated in  FIG.  13   . 
         FIG.  16    illustrates an example of the computer synchronizing its DRM content with a portable player. 
         FIG.  17    conceptually illustrates a process that a computer performs in some embodiments to synchronize a set of content with a portable player. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description, numerous details are set forth for the purpose of explanation. However, one of ordinary skill in the art will realize that the invention may be practiced without the use of these specific details. In other instances, well-known structures and devices are shown in block diagram form in order not to obscure the description of the invention with unnecessary detail. 
     I. Media Storage Structure 
     Some embodiments of the invention provide a content-distribution system for distributing unitary media storage structures to devices (e.g., computers, portable players, etc.) that connect to a network. Each unitary media storage structure includes a set of related pieces of content. In at least some unitary media storage structures of some embodiments, each piece of content is separately encrypted to protect it from unauthorized use. Examples of pieces of content include video, audio, text, sound, etc. 
       FIG.  1    conceptually illustrates an example of a unitary media storage structure  100  of some embodiments. As shown in this figure, the media storage structure includes first and second pieces  105  and  110  of encrypted content. It also includes first and second sections  115  and  120  for containing first and second cryptographic keys for decrypting the first and second pieces  105  and  110  of content. The media storage structure also includes a header  125  that includes metadata regarding the content in the media storage structure. 
     Based on whether the device is allowed to access the first piece of content  105 , the second piece of content  110 , or both, the system provides the device with a set of keys for decrypting the pieces of the content that the device is able to access. The provided set of keys might include only one key for decrypting only one of the two encrypted pieces of content. Alternatively, it might include two keys for decrypting both encrypted pieces of content. 
     For instance,  FIG.  2    illustrates an example where the selected set of keys includes a first key  215  for decrypting the first encrypted piece of content  105  and a second key  220  for decrypting the second encrypted piece of content  110 .  FIG.  3    illustrates another example of the media storage structure  100 . In this example, the media storage structure  100  includes only the second key  220  for decrypting the second piece of encrypted content  110 . 
     Based on the set of keys that the system provides to the device, the device can decrypt and access either one of the two pieces of content  105  and  110  or both pieces of encrypted content. The system of some embodiments distributes the media storage structure with the encrypted first and second content pieces  105  and  110  from a computer that is separate from the computer or computers that distribute the first and second keys  215  and  220  for decrypting the first and second pieces of encrypted content. 
     While this application describes receiving, storing, manipulating and using a “key,” it will be understood that a host of know techniques can be used to disguise the key. For example, key hiding, key encryption, splitting the key into more than one piece to be stored separately, and obfuscation of read/write operations, can all be used and are considered within the general concept of receiving, storing, and using a “key.” 
     As mentioned above, the single media storage structure that is distributed by some embodiments includes a set of related pieces of content. In some embodiments, two pieces of content are related when they relate to the same audio and/or video presentation (e.g., song, movie, music video, etc.). In some cases, two pieces of related content can be viewed or played simultaneously. In other cases, two pieces of related content can be viewed or player independently. 
       FIGS.  4 - 10    illustrate various examples of related pieces of content in a media storage structure of some embodiments.  FIG.  4    illustrates an example of a storage structure  400  where one piece of encrypted content is audio content  405  (e.g., an audio track, a song, a sound track) related to a particular presentation (e.g., a music video, a film, etc.), while the other piece of encrypted content is video content  410  (e.g., a video track, a video clip, etc.) related to the particular presentation. 
       FIG.  5    illustrates a storage structure  500  that includes two pieces of video content. One example of two such pieces of video content would be two video clips that are shot from different angles to cover one or more scenes in a movie. A piece of video content might also include audio content associated with its video content or might only include video data.  FIG.  6    illustrates a storage structure  600  that includes two pieces of audio content. One example of two such pieces of audio content would be two different versions or mixes of a song. 
     Content other than audio or video might be stored in the media storage structure of the some embodiments of the invention. For instance,  FIG.  7    illustrates a media storage structure  700  that stores one piece of audio content  705  and another piece of textual content  710 , which might be lyrics, dialogue, or other data associated with the audio content  705 . Similarly,  FIG.  8    illustrates a media storage structure  800  that stores one piece of video content  805  and another piece of textual content  810 , which might be dialogue associate with the video content  805 . 
     In some cases, the system distributes a media storage structure that contains more than two pieces of content. For instance,  FIG.  9    illustrates a media storage structure  900  that includes one piece of audio content (e.g., a song) along with two pieces of video content, which can be two different video clips associated with the audio content (e.g., can be two different music videos that are associated with the song). Similarly,  FIG.  10    illustrates a media storage structure  1000  that includes one piece of video content (e.g., a movie) along with two pieces of audio content, which can be the video&#39;s audio component in two different languages. 
     In the various examples illustrated in  FIGS.  4 - 10   , the media storage structure includes a key for decrypting each piece of content stored in the media storage structure. As mentioned above, the content-distribution system of some embodiments allows different set of keys to be acquired (e.g., purchased or licensed) for accessing a media storage structure on a particular device. In some embodiments, the device stores the acquired set of keys in the media storage structure, and uses the acquired set of keys to decrypt and access the media storage structure&#39;s content that has been purchased or licensed for access on the device. Once decrypted, the device can individually or simultaneously view or play the decrypted pieces of content. 
     In some embodiments, the device (e.g., the computer) that receives the media storage structure transfers the media storage structure to another device (e.g., to a portable player). In this transfer, one of the pieces of content from the media storage structure might be removed in the transfer of the media storage structure to the other device (e.g., in the portable player). In some cases, one of the pieces of content is removed in order to reduce the consumption of resources on the other device. 
     Some embodiments above were illustrated by reference to a media storage structure that itself includes a plurality of sections available for storage of keys. Such storage sections can be incorporated into many media file formats, including the Quicktime file format, Windows Media file format, Real media format, ISO/IEC 14496-12, Motion JPEG, etc. One of ordinary skill will realize that in some embodiments the keys are alternatively stored and transferred separately from the unitary media files to which they pertain. 
     II. Content-Distribution System 
       FIG.  11    illustrates a content-distribution system  1100  of some embodiments. This content-distribution system distributes content in a manner that protects the digital rights (i.e., ensures the legal use) of the content. To distribute content that is related, the system distributes single media storage structures with multiple related pieces of content. In this example, the media storage structures are media files. One of ordinary skill will realize that other embodiments might use other types of storage structures. 
     As shown in  FIG.  11   , the content-distribution system  1100  includes a content-caching server  1105 , a DRM server  1110 , and a content-receiving computer  1115 . The computer  1115  connects to the servers  1105  and  1110  through a computer network, such as a local area network, a wide area network, a network of networks (e.g., the Internet), etc. 
     Through this connection, the computer  1115  communicates with the DRM server  1110  to obtain content. In some embodiments, the content-distribution system  1100  does not entail the sale or licensing of content. Accordingly, in these embodiments, the DRM server  1110  simply enforces the distribution of content to authorized computers without considering any financial objectives. 
     For purposes of illustration, however, several embodiments of the content-distribution system  1100  that are described below are involved in the sale or licensing of the content. Accordingly, in these embodiments, the DRM server  1110  is the server from which the user of the computer  1115  can purchase or license content. In other words, the DRM server  1110  of some embodiments is the server that handles the financial transaction for purchasing or licensing content. In some instance, certain content can be purchased or licensed free. 
     After the DRM server  1110  determines that the computer  1115  can obtain the content, the content-distribution system  1100  uses the content caching server  1105  to provide a media storage file that contains one or more pieces of DRM content to the computer  1115  through the network  1120 . In some embodiments, the system  1100  uses multiple caching servers  1105  to cache content at various locations on the network, in order to improve the speed and efficiency of downloading content across the network. For each media storage file that the DRM server  1110  directs the caching server  1105  to provide to the computer  1115 , the DRM server  1110  provides a set of keys for the computer to use to decrypt the content that is stored in the media storage file. 
       FIG.  12    conceptually illustrates an example of one possible set of interactions between the computer  1115 , the DRM server  1110 , and the content-caching server  1105 . This set of interactions represents a content-acquisition process  1200  of some embodiments of the invention. As shown in this figure, the acquisition process  1200  starts when the computer  1115  sends (at  1205 ) a request to the DRM server  1110  to purchase or license one or more pieces of content that are stored in a particular media file. At  1210 , the DRM server receives this request. 
     The acquisition process then has the DRM server  1110  and/or purchasing computer  1115  perform one or more operations (at  1215 ) to complete the purchase or license transaction. After the transaction has been completed, the DRM server  1110  sends (at  1215 ) a request to the content-caching server  1105  to send the media file for the purchased or licensed content to the computer  1115 . 
     The caching server  1105  receives this request at  1225 , and in response, commences (at  1230 ) a download of the media file to the purchasing computer  1115 .  FIG.  11    illustrates an example of a media file  1125  that the content caching server  1105  downloads to the computer  1115 . In this example, the media file has five sections. The first and second section  1145  and  1155  contain two pieces of encrypted content. Each piece of content is encrypted using a particular content key. The third and fourth sections  1150  and  1160  are empty sections in the file for the insertion of the content keys if such content keys are purchased or licensed by the computer  1115 . Lastly, the fifth section  1165  is a header field, which contains metadata regarding the content and/or content keys. 
     The computer  1115  receives (at  1235 ) the media file provided by the caching server. The computer  1115  then sends (at  1240 ) a confirmation of the download to the DRM server  1110 . After  1220 , the DRM server  1110  transitions to a wait state  1245  to wait for the confirmation to be received from the computer  1115 . 
     Once the DRM server  1110  receives the confirmation of the download at  1245 , it sends (at  1250 ) to the computer  1115  a set of keys based on the pieces of content that the computer  1115  purchased or licensed. In the example illustrated in  FIG.  11   , the computer  1115  has acquired both pieces of content that is stored in the media file. Accordingly, in this example, the DRM server  1110  sends (at  1250 ) a set of keys that would allow the computer  1115  to access both pieces of content in the media file  1125 . 
     In the example illustrated in  FIG.  11   , this set of keys includes two content keys  1130  and  1132 . In some embodiments, each piece of content (e.g.,  1145  or  1155 ) is encrypted based on a particular content key (e.g.,  1130  or  1132 ). Hence, the computer  1115  uses the content key  1130  to decrypt the encrypted content  1145 , and uses the content key  1132  to decrypt the encrypted content  1155 . 
       FIG.  13    illustrates another example of the computer  1115  acquiring the media file  1125 . In this example, the computer  1115  has only acquired the first encrypted content  1145 . Accordingly, even though the caching server  1105  supplies the computer  1115  with the media file that contains both pieces of content, the DRM server  1110  only supplies the content key  1130  for the encrypted content  1145 . 
     Accordingly, in this example, the computer can access the encrypted content  1145  in the media file by using the content key  1130 . However, since the computer  1115  has not received the encrypted content for the encrypted content  1155  in the media file  1125 , the computer cannot decrypt the encrypted content  1155 . 
     As shown in  FIG.  12   , the computer  1115  receives (at  1255 ) the set of keys supplied by the DRM server  1110 . As shown in  FIG.  12   , the computer  1115  stores (at  1260 ) this set of keys in the media file.  FIG.  14    illustrates the computer&#39;s storage of the two keys that it receives in the example illustrated in  FIG.  11   . As shown in this figure, the computer  1115  initially stores the content keys  1130  and  1132  in temporary storages  1405  and  1407 . It then merges these content keys with the media file  1125  that it received at  1235  and that it temporarily stored in a temporary storage  1410 . The computer then stores the media file that results from this merging in a content library storage  1415 . 
       FIG.  15    illustrates the computer&#39;s storage of the key that it receives in the example illustrated in  FIG.  13   . The storage operation illustrated in  FIG.  15    is similar to the storage operation illustrated in  FIG.  14   , except that the merge file (stored in the content media library  1415 ) does not contain the content key  1132  for the second encrypted content as the computer did not acquire and receive this content key. 
     In the embodiments described above, the content-distribution system  1100  utilizes one computer to provide the encrypted content while using another computer to provide the keys necessary for decrypting the encrypted content. One of ordinary skill will realize that in other embodiments the content-distribution system utilizes one computer to provide encrypted content and the keys for decrypting the encrypted content. 
     Alternatively, in other embodiments, the content-distribution system uses more than one computer to provide the cryptographic keys for the content. For example, keys for audio content may be available from one server and keys for related video content stored in the same media storage structure may be available from a separate server. The multiple servers may even be owned and administered by different parties, as may be the rights they administer. 
     Also, in the embodiments described above, the content-distribution system  1100  provides different cryptographic keys for decrypting different pieces of content. In other embodiments, the content-distribution system might utilize different encoding schemes for encrypting different pieces of content. For instance, the system might utilize a symmetric encoding scheme to encrypt audio content but utilize an asymmetric encrypting scheme to encrypt video content. Alternatively, the system might encrypt audio content in its entirety, while encrypting only parts of the video content. 
     Also,  FIG.  12    illustrates one possible set of interactions between the computer  1115 , the DRM server  1110 , and the caching server  1105 . One of ordinary skill will realize that these computers might interact differently in other embodiments. For instance, in some embodiments, the computer  1115  does not send a confirmation of the receipt of a media file to the DRM server. In some of these embodiments, the DRM server on its own sends the set of keys to the computer  1115 . 
     Although some embodiments have been described with reference to a simplified network configuration, it will be understood that many variations exist within the framework described herein. For example, the DRM server is shown as a single computer, but for the purposes of this patent, such a server could include many interconnected computers and/or memory and/or interconnecting pieces of equipment. Similarly, the content caching server could be a single computer or a collection of networked computers and memory all forming a server. Additionally, while content may be supplied from a content caching server directly or indirectly to a specific client computer, other transfer methods may result in a computer requiring keys to unlock content available to it from a peer computer, portable storage device, or some other transfer mechanism. 
     III. Synchronization with a Player 
     In some embodiments, the computer  1115  can synchronizes its DRM content with a portable player that is also allowed access to the DRM content. In some cases, this synchronization removes one or more pieces of content from a media file that the computer downloads to the portable player. In some cases, the pieces of content are removed in order to reduce the consumption of resources on the other device. In other cases, content is removed from the media storage structure because the other device does not have rights to access this other content. 
       FIG.  16    illustrates an example of the computer  1115  synchronize its DRM content with a portable player  1605 . The portable player can be a music player, audio/video player, etc. When the computer  1115  synchronizes its DRM content with the player  1605 , the portable player  1605  in some embodiments receives (1) DRM content from the computer  1115 , and (2) a content key for decrypting each piece of DRM content that it receives. The portable then stores the received encrypted DRM content and the associated keys. 
       FIG.  17    conceptually illustrates a process  1700  that a computer  1115  performs in some embodiments to synchronize a set of content with a player  1605 . As shown in this figure, the process  1700  starts (at  1705 ) when it receives a request to synchronize a set of content with the player  1605 . The process then identifies (at  1710 ) the set of media files that is associated with a user account ID of the player. 
     Next, the process determines (at  1715 ) whether the computer  1115  is storing any media file for the player, which it has not yet downloaded to the player (i.e., whether there is any media file that needs to be synchronized between the computer and the player). If not, the process ends. 
     Otherwise, the process selects (at  1720 ) a media file that needs to be synchronized. At  1720 , the process removes from the media file any piece of content that has been designated as content that should not be downloaded to the portable player. In some embodiments, the computer uses an application that allows a user to designate the content that the user wishes to synchronize with the portable player. 
     If the process removes (at  1720 ) any content from the media file, it also removes the content&#39;s associated content key and metadata from the media file in some embodiments of the invention.  FIG.  16    illustrates an example of the removal of the video content and its associated content key from a media file  1600  that is downloaded to the portable player  1605 . 
     After  1720 , the process downloads (at  1725 ) the media file that contains only the encrypted content that has to be synchronized with the player (i.e., downloads the media file after any content that should not be downloaded to the player has been removed). In some embodiments, the downloaded media file not only contains one or more pieces of encrypted content but also contains one or more content keys that can be used to decrypt the content. In some embodiments, the set of keys that is downloaded in the media file to the player is the same set of keys that are used to decrypt the content on the computer  1115 . In other embodiments, the keys in the downloaded media file are a different set of keys. 
     The player then stores (at  1725 ) the downloaded media file on its internal storage (e.g., its internal non-volatile storage, hard drive, flash memory, etc.). After  1725 , the process determines (at  1730 ) whether there is any additional content for the player that it has not yet downloaded to the player (i.e., whether there is any additional content that needs to be synchronized between the computer and the player). If so, the process repeats  1720  and  1725  for a piece of content that needs to be synchronized. If not, the process ends. 
       FIG.  17    provides an illustrative example of synchronizing media files between a computer and a player in some embodiments of the invention. One of ordinary skill will realize that other embodiments use other processes for synchronizing media files. Also, in some embodiments, the portable player directly communicates with the DRM server and/or the content caching server to obtain content. 
     IV. Encryption 
     As described above, several embodiments of the invention provide DRM processes and systems for distributing content. These processes and systems encrypt and decrypt content based on cryptographic keys. Encrypting content entails transforming the content from a decipherable form (called plaintext) into an indecipherable form (called ciphertext) based on one or more cryptographic keys. Decrypting content entails transforming encrypted content into a decipherable from by using one or more cryptographic keys. 
     An encryption key is a piece of information that controls the operation of a cryptography algorithm. In symmetrical encryption technology, the key that is used to encrypt content is the same key that is used to decrypt content. In asymmetric encryption technology, the same key is not used to encrypt and decrypt the content. For instance, in one scheme, an encrypting device uses a public key of a recipient to encrypt content, and the recipient uses its private key to decrypt the encrypted content. 
     Many of the features of the embodiments described above can be implemented according to a symmetrical or asymmetrical encryption approach. Also, in some embodiments, the encryption is applied to a binary format of the content. Although the unencrypted binary format of a piece of content may be hard for a human to decipher, it can be deciphered by an application or an operating system. On the other hand, encrypted binary format of a piece of content ideally should not be deciphered by any application or operating system, without first being decrypted by using one or more cryptographic keys. 
     While the invention has been described with reference to numerous specific details, one of ordinary skill in the art will recognize that the invention can be embodied in other specific forms without departing from the spirit of the invention. For instance, even though one set of keys are described above for the media storage files of some embodiments, other embodiments provide different sets of keys for defining different levels of access on different devices to the content of a media storage file. Thus, one of ordinary skill in the art would understand that the invention is not to be limited by the foregoing illustrative details, but rather is to be defined by the appended claims.

Metadata:
Filing Date: 20190520
Publication Date: 20230815
Grant Date: 20230815
Priority Date: 20051011
Inventors: FARRUGIA, AUGUSTIN J.
DOWDY, THOMAS
FASOLI, GIANPAOLO
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F21/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q20/1235", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F21/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F21/6218", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N21/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q2220/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F21/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F21/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06Q20/1235", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F21/6218", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q2220/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F21/6218", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q20/1235", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N21/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q2220/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N21/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06Q2220/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F21/6218", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 37668179