Abstract: A method and apparatus for playing back a media content instance is disclosed. The method permits the use of downloadable variants to upgrade or change cryptographic functions performed by the playback device, thus permitting content protection schemes to be renewed.

Abstract: A system, method, and computer program product to renewably prevent traitors in a broadcast encryption system from re-using compromised keys. A license agency assigns individual receivers a set of Sequence Keys preferably at manufacture, and assigns Sequence Key Blocks (SKBs) to protected content files to be distributed. The files may be distributed on prerecorded media and typically include several file modifications. The particular modifications in a pirated version of a file can help identify which traitors contributed to its theft. SKBs assigned to new files distributed after traitors have been identified cannot be usefully processed using the compromised keys employed in previous content piracy. Innocent receivers that happen to have compromised key(s) in common with traitors can use a replacement uncompromised Sequence Key from the set to usefully decrypt content. Traitors will however step through all their Sequence Keys without reaching one that will work.

Abstract: A system and method is disclosed for performing unified broadcast encryption and traitor tracing for digital content. In one embodiment a media key tree is divided into S subtrees, the media key tree including media keys and initial values, which may be random values. The digital content is divided into a plurality of segments and at least some of the segments are converted into a plurality of variations. The random values are transformed into media key variations and a separate media key variant is assigned to each of the subdivided subtrees. A unified media key block including the media key tree is stored on the media.

Abstract: A system and method is disclosed for performing unified broadcast encryption and traitor tracing for digital content. In one embodiment a media key tree is divided into S subtrees, the media key tree including media keys and initial values, which may be random values. The digital content is divided into a plurality of segments and at least some of the segments are converted into a plurality of variations. The random values are transformed into media key variations and a separate media key variant is assigned to each of the subdivided subtrees. A unified media key block including the media key tree is stored on the media.

Abstract: Provided are techniques to enable, using broadcast encryption, a device to locate a service offered by a server with the knowledge that the service offered by the server is a trusted service. A signed enhanced Management Key Block (eMKB) includes a trusted service locator (TSL) that includes one or more records, or “trusted service data records” (TSDRs), each identifying a particular service and a corresponding location of the service is generated and transmitted over a network. Devices authorized to access a particular service parse the eMKB for the end point of the service, connect to the appropriate server and transmit a request.

Abstract: Embodiments of the present invention relate to providing encrypted content to authorized content consumers while providing robust traitor tracing. In some embodiments, at least one device key is read. A key block is read. A media key precursor is determined from the key block and the at least one device key. At least one encrypted block key is read. A block master key is determined from the media key precursor. A security program is executed to determine a decrypted block key from the media key precursor, the block master key, and the encrypted block key. The decrypted block key is provided for application to the encrypted content to obtain decrypted content.

Abstract: A system, method, and computer program product to renewably prevent traitors in a broadcast encryption system from re-using compromised keys. A license agency assigns individual receivers a set of Sequence Keys preferably at manufacture, and assigns Sequence Key Blocks (SKBs) to protected content files to be distributed. The files may be distributed on prerecorded media and typically include several file modifications. The particular modifications in a pirated version of a file can help identify which traitors contributed to its theft. SKBs assigned to new files distributed after traitors have been identified cannot be usefully processed using the compromised keys employed in previous content piracy. Innocent receivers that happen to have compromised key(s) in common with traitors can use a replacement uncompromised Sequence Key from the set to usefully decrypt content. Traitors will however step through all their Sequence Keys without reaching one that will work.

Abstract: A method and apparatus for playing back a media content instance is disclosed. The method permits the use of downloadable variants to upgrade or change cryptographic functions performed by the playback device, thus permitting content protection schemes to be renewed.

Abstract: Embodiments of the present invention relate to providing encrypted content to authorized content consumers while providing robust traitor tracing. In some embodiments, at least one device key is read. A key block is read. A media key precursor is determined from the key block and the at least one device key. At least one encrypted block key is read. A block master key is determined from the media key precursor. A security program is executed to determine a decrypted block key from the media key precursor, the block master key, and the encrypted block key. The decrypted block key is provided for application to the encrypted content to obtain decrypted content.

Abstract: A method and system for attaching a title key to encrypted content for synchronized transmission to, or storage by, a recipient is provided. Specifically, under the present invention, an elementary media stream is parceled into content units that each include a content packet and a header. The content packets are encrypted with one or more title keys. Once the content packets have been encrypted, the title keys are themselves encrypted with a key encrypting key. The encrypted title keys are then attached to the corresponding encrypted content packets for synchronized transmission to a recipient.

Abstract: Embodiments of the present invention relate to providing encrypted content to authorized content consumers while providing robust traitor tracing. In one embodiment, a key bundle comprising at least one device key is read. A key block is read. A media key precursor is determined from the key block and the at least one device key. A security program is read. At least one encrypted block key is read. The security program is executed to determine a decrypted block key from the media key precursor and the encrypted block key. Encrypted content is read. The decrypted block key is applied to the encrypted content to obtain decrypted content.

Abstract: Embodiments of the present invention relate to providing encrypted content to authorized content consumers while providing robust traitor tracing. In one embodiment, a key bundle comprising at least one device key is read. A key block is read. A media key precursor is determined from the key block and the at least one device key. A security program is read. At least one encrypted block key is read. The security program is executed to determine a decrypted block key from the media key precursor and the encrypted block key. Encrypted content is read. The decrypted block key is applied to the encrypted content to obtain decrypted content.

Abstract: Provided are techniques for the creation and storage of an archive for binding IDs corresponding to a cluster of devices that render content protected by a broadcast encryption scheme. When two or more clusters are merged, a binding ID corresponding to one of the clusters is selected and a new management key is generated. Binding IDs associated with the clusters other than the cluster associated with the selected binding ID are encrypted using the new management key and stored on a cluster-authorized device in a binding ID archive. Content stored in conformity with an outdated binding ID is retrieved by decrypting the binding ID archive with the management key, recalculating an old management key and decrypting the stored content.

Abstract: Provided are techniques for the creation and storage of an archive for binding IDs corresponding to a cluster of devices that render content protected by a broadcast encryption scheme. When two or more clusters are merged, a binding ID corresponding to one of the clusters is selected and a new management key is generated. Binding IDs associated with the clusters other than the cluster associated with the selected binding ID are encrypted using the new management key and stored on a cluster-authorized device in a binding ID archive. Content stored in conformity with an outdated binding ID is retrieved by decrypting the binding ID archive with the management key, recalculating an old management key and decrypting the stored content.

Abstract: Provided are techniques to enable a device that provides a service to authorize a second device for receiving the service and the delivery of the service to the second device and other devices within a trusted network. A signed Management Key Block (MKB) is generated and transmitted over a network. Devices authorized to access a particular service parse the MKB and transmit a request. A server associated with the service determines whether or not the device is authorized to access the service based upon data included in the request. The first device may issue a challenge to the second device for authentication purposes. If service is approved, service is initiated, either from the first device or another authorized device. Devices may be organized into classes such that devices of a specific class are authorized to access the service.

Abstract: The present invention provides a method, system and program product for modifying content usage conditions during broadcast content distribution. Specifically, the present invention allows protected (e.g., encrypted, secured, etc.) content to be received along with content usage conditions, an encrypted combination of the content usage conditions and a title key (e.g., a MAC), and a key management block. Using the key management block, a key encrypting key can be determined for decrypting the combination. Once the combination is decrypted, the content usage conditions can be modified (e.g., edited, added to, etc.).

Abstract: A first message comprising a received indication of a management key block (MKB) and a received indication of an authorization table (AT) is received at a first network device from a second network device. The received indications of the MKB and AT are validated by comparing them to generated indications of the MKB and AT, respectively. A response is generated based on the validation of the received indications and transmitted from the first network device to the second network device. The generated indications and response are stored. A second message comprising a second received indication of the MKB and a second received indication of the AT is received at the first network device from the second network device. The first network device communicates with the second network device in accordance with the stored response on determining that the second received indications match corresponding stored indications.

Abstract: Embodiments of the invention relate to finding coalitions of receivers who collude to produce pirated protected content, then evaluates the confidence that particular members of each identified coalition are traitors versus innocent receivers incriminated by chance. Typically, each file in a group of original files is modified to include variations of critical file segments. The group of files is then broadcast with individualized codes that enable particular authorized receivers to properly process the modified files. The modifications in a pirated version of a file can identify which traitorous receivers contributed to its piracy. Candidate coalitions of differing size are first evaluated to determine if they cover observed file variations with greater than a predetermined likelihood that an innocent coalition is falsely incriminated by chance. Individual members of satisfactory coalitions are then evaluated. Traitors may be cryptographically revoked.

Abstract: Provided are techniques for the creation and storage of an archive for binding IDs corresponding to a cluster of devices that render content protected by a broadcast encryption scheme. When two or more clusters are merged, a binding ID corresponding to one of the clusters is selected and a new management key is generated. Binding IDs associated with the clusters other than the cluster associated with the selected binding ID are encrypted using the new management key and stored on a cluster-authorized device in a binding ID archive. Content stored in conformity with an outdated binding ID is retrieved by decrypting the binding ID archive with the management key, recalculating an old management key and decrypting the stored content.

Abstract: A cryptographic authentication system comprises an authentication media key block that comprises media key precursors. The system generates transformed keys by applying a function to a media ID of a media and each of the media key precursors, and generates entries in a binding table by applying an encrypting function to a media key of an encrypted content and each of the transformed keys. To play encrypted content, a media player processes the authentication media key block using a device key to extract a media key precursor, extracts a media key from the binding table using the extracted media key precursor and the media ID, and verifies that the extracted media key matches the media key of the encrypted content, allowing the media device to decrypt and play the encrypted content.