| Patent application number | Description | Published |
|---|
| 20080279376 | SYSTEM, METHOD, AND SERVICE FOR PERFORMING UNIFIED BROADCAST ENCRYPTION AND TRAITOR TRACING FOR DIGITAL CONTENT - A unified broadcast encryption system divides a media key tree into S subtrees, divides digital content into segments, and converts some of the segments into variations; the number of segments and variations is q. The system subdivides each of the subtrees into q/|S| subdivided subtrees, assigns a key media variant to each of the subdivided subtrees, and generates a unified media key block (MKB | 11-13-2008 |
| 20090049308 | Method for Effective Tamper Resistance - A system, method, and computer program product for preventing a malicious user from analyzing and modifying software content. The one-way functions used in prior art systems using dynamically evolving audit logs or self-modifying applications are replaced with a one-way function based on group theory. With this modification, untampered key evolution will occur inside a defined mathematical group such that all valid key values form a subgroup. However, if the program is altered, the key will evolve incorrectly and will no longer be a member of the subgroup. Once the key value is outside of the subgroup, it is not possible to return it to the subgroup. The present invention provides a limited total number of valid keys. The key evolution points are not restricted to locations along the deterministic path, so the key can be used in various novel ways to regulate the program's behavior, including in non-deterministic execution paths. | 02-19-2009 |
| 20090049558 | SYSTEM AND METHOD FOR TRACING TARDOS FINGERPRINT CODES - A system and method is provided for identifying the source of an unauthorized copy of content. The method includes embedding a unique user fingerprint code to into each of a plurality of authorized copies of content and identifying an unknown fingerprint code in an unauthorized copy of the content. Each member of the unknown fingerprint code is compared to each corresponding member in each of the user fingerprint codes. A score is assigned to each of the user fingerprint codes based on the comparison and users associated with scores exceeding a threshold are identified as a source of the unauthorized copy. | 02-19-2009 |
| 20090049560 | System and Method for Tracing Tardos Fingerprint Codes - A system and method is provided for identifying the source of an unauthorized copy of content. The method includes embedding a unique user fingerprint code to into each of a plurality of authorized copies of content and identifying an unknown fingerprint code in an unauthorized copy of the content. Each member of the unknown fingerprint code is compared to each corresponding member in each of the user fingerprint codes. A score is assigned to each of the user fingerprint codes based on the comparison and users associated with scores exceeding a threshold are identified as a source of the unauthorized copy. | 02-19-2009 |
| 20090214029 | Unified Broadcast Encryption System - 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. | 08-27-2009 |
| 20090214031 | UNIFIED BROADCAST ENCRYPTION SYSTEM - 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. | 08-27-2009 |
| 20090319227 | ADAPTIVE TRAITOR TRACING - One embodiment of the present invention includes a method for traitor tracing that selects a probability distribution for the assignment of file-segment variations in a digital file. This probability distribution is selected to improve traceability for a particular size of a coalition of attackers. At least one symbol for each file-segment variation is then distributed based on the selected probability distribution. | 12-24-2009 |
| 20090320130 | TRAITOR DETECTION FOR MULTILEVEL ASSIGNMENT - One embodiment of the present invention includes a method for traitor tracing that includes performing an inner code traitor tracing on a recovered pirated digital file, the recovered digital file incorporating an inner code for assigning segments of the digital file and an outer code for assigning inner codes to individual digital files. The method also includes extracting partial information regarding the outer code from the inner code tracing. An outer code tracing procedure may then be performed using the partial information. | 12-24-2009 |
| 20090327717 | SYSTEM, METHOD, AND SERVICE FOR TRACING TRAITORS FROM CONTENT PROTECTION CIRCUMVENTION DEVICES - A traitor tracing system generates a hypothesized model of the circumvention device that models a hypothesized set of device keys compromised by the circumvention device. The system iteratively invokes a subset tracing system to identify a compromised device key until substantially all the compromised device keys in the set of compromised device keys are identified so as to disable the circumvention device. A subset tracing system generates a circumvention device model that models behavior of a circumvention device using prior knowledge and The system iteratively selects and applies to the circumvention device a test based on the hypothesized model and the circumvention device model and receives a response from the circumvention device indicating a success of the test in playing protected content on the circumvention device. The system updates the hypothesized model using the received response, the selected test, a current version of the hypothesized model, and a current version of the circumvention device model to focus the test selecting process in determining the device keys obtained from the traitor. | 12-31-2009 |
| 20100040231 | Security Classes in a Media Key Block - According to one embodiment of the present invention, a method for broadcast encryption with security classes in a media key block is provided. In one embodiment the method includes receiving encrypted media of a first and a second class, where the media includes a common media key block, in a device of a first class and in a device of a second class. A first media key is calculated from the common media key block in the device of a first class. A first media key precursor is calculated from the common media key block in the device of a second class. The first media precursor may be used to decrypt media of a first class. The first media precursor may also be used to calculate a second media key in the device of a second class to decrypt content of a first class. | 02-18-2010 |
| 20100183148 | RECORDING KEYS IN A BROADCAST-ENCRYPTION-BASED SYSTEM - According to one embodiment of the present invention, a method for protecting content in a broadcast-encryption-based system, where the devices in the system receive a recording key table. Each device generates a set of recording keys from the recording key table using a media key variant calculated from the broadcast encryption system's media key block. The digital content is encrypted in a title key picked by the recorder. The selected title key is also encrypted in each one of the recorder's generated recording keys. To play back the content, a player uses one of its generated recording keys to decrypt the title key and the decrypt the content. The recording key table is designed so that any two devices are guaranteed to have at least one key in common during normal operation, although during a forensic situation, this rule can be abandoned. | 07-22-2010 |
| 20100218000 | CONTENT DISTRIBUTION WITH RENEWABLE CONTENT PROTECTION - A method of renewing encryption applied to a content file in a playback device comprising determining a specified variant of at least one microcode function to be used in playing back the content file, determining if variants are stored in internal memory on the playback device to determine if the specified variant is included in the stored variants, retrieving the specified variant from a variant storage in a memory located in a media device in communication with the playback device, if the specified variant is not included in the stored variants, and using the specified variant to access the content file. A playback device has at least one memory having a variant storage, the variant storage including at least one variant of a microcode function, and a processor configured to execute instructions to determine at least one specified variant, access the variant storage of at least one memory to acquire the specified variant, and use the specified variant to decrypt a content file downloaded to a media device in communication with the playback device. | 08-26-2010 |
| 20100299458 | SIMPLE NONAUTONOMOUS PEERING MEDIA CLONE DETECTION - A playback device includes a port configured to receive content from an external memory device, a device memory residing in the device, and a controller programmed to execute instructions that cause the controller to read a read data pattern from the defined region in the external memory device and determine if the read data pattern correlates to an expected data pattern to a predetermined level, wherein the expected data pattern is derived at least in part from a defect map of the defined region. A memory device includes an array of memory cells configured to store at least one bit of data, the array of memory cells being organized into regions, at least one first region of the array of memory cells having stored therein a defect map of the array of memory cells, and at least one second region of the array of memory cells being designated as a defined region having a known defect pattern. A method of validating a memory device includes writing, using a controller in a playback device, a known data pattern to a defined region in the memory device, reading, with the controller, a read data pattern from the defined region, comparing, at the controller, the read data pattern to an expected data pattern, the expected data pattern derived from the known data pattern and a defect map of the defined region, and validating, with the controller, the memory device based upon a correlation result from the comparing. | 11-25-2010 |
| 20110026710 | System and Method for Cryptographically Authenticating Data Items - 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. | 02-03-2011 |
