摘要:
A method (and system) for storing information in a recoverable manner on an untrusted system, includes sending, by a client, a request to a recovery server for recovery of a failed database, determining whether the request is legitimate, based on the determining, sending a local key to the client, decrypting by the client the failed database with the local key, to recover the failed database, and re-encrypting the recovered database with a new key.
摘要:
A method and system for client/server communications in which stored user information controls revealed and delivered information. A client system is Communicatively coupled to a server through an intermediate system, which acts as a persona module. User information about a user on the client system is stored on the client system. Information about advertising information is stored on the server. The intermediate system receives information about user information from the client system and information about advertising information from the server. The intermediate system acts as a user's agent to filter out irrelevant advertisement material. The intermediate system can also function to customize the advertisements received by the client system from the server, but not returning information about the user's interest or preferences to the server. A user's privacy may be further protected if the information returned to a server is at least partially untruthful.
摘要:
An information processing system including an encryption processing logic module and a decryption processing logic module for enabling the encryption of digital information to be decrypted with a decryption key K. The encryption processing module includes logic for encrypting the digital information, distributing the digital information and authorizing a user to decrypt the information. The decryption processing module includes logic for the user to communicate a user number n.sub.i to receive an authorization number a.sub.i from the authorization logic in the encryption processing module and extrication logic for extricating the decryption key. The user number n.sub.i uniquely identifies, and is valuable to, the user, so valuable in fact that the user would be unwilling to publically dislcose it. The extrication logic operates on a digital signet pair (a.sub.i, n.sub.i) consisting of the authorization number and user number, to extract K. The decryption logic then uses K to make the content available to the user. The extrication function is fully available to the user as a publicly-computable function in which it is computationally infeasible to use the extrication function to determine other valid digital signet pairs which can be used to extract K.
摘要:
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.
摘要:
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.
摘要:
A system and method for enabling broadcast programs to be copied once only by consumer recorders includes writing a unique media identification on each blank disk to which content is to copied in a read-only area of the disk before it is initially recorded. Also, a one-way key management media key block is written to the disk. A content key is derived by combining a media key, derived from the media key block, with the media identification. Additionally, to facilitate copying the content one time only, an exchange key is established between the recorder and a sender such as a satellite receiver or a disk player that is associated with the recorder, and the exchange key is modified with one or more special numbers representing control commands including copy once and copy no more. The modified exchange key is then encrypted using the content key to render an encrypted modified exchange key, and the encrypted modified exchange key is then hashed with a nonce to render a bus content key. The bus content key is then used to encrypt the data for copying the data to a disk. Unauthorized attempts to copy the data after the first authorized copy has been made cannot succeed because the media ID is different on subsequent blank media. Further, if illegal clones are manufactured that can calculate the media key, new blank media can change the media key block such that the clones can no longer calculate the correct media key. Authorized players, however, can decrypt the data to display it.
摘要:
A tree is used to partition stateless receivers in a broadcast content encryption system into subsets. Two different methods of partitioning are disclosed. When a set of revoked receivers is identified, the revoked receivers define a relatively small cover of the non-revoked receivers by disjoint subsets. Subset keys associated with the subsets are then used to encrypt a session key that in turn is used to encrypt the broadcast content. Only non-revoked receivers can decrypt the session key and, hence, the content.
摘要:
A system and method for enabling broadcast programs to be copied once only by consumer recorders includes writing a unique media identification on each blank disk to which content is to copied in a read-only area of the disk before it is initially recorded. Also, a one-way key management media key block is written to the disk. A content key is derived by combining a media key, derived from the media key block, with the media identification. Additionally, to facilitate copying the content one time only, an exchange key is established between the recorder and a sender such as a satellite receiver or a disk player that is associated with the recorder, and the exchange key is modified with one or more special numbers representing control commands including copy once and copy no more. The modified exchange key is then encrypted using the content key to render an encrypted modified exchange key, and the encrypted modified exchange key is then hashed with a nonce to render a bus content key. The bus content key is then used to encrypt the data for copying the data to a disk. Unauthorized attempts to copy the data after the first authorized copy has been made cannot succeed because the media ID is different on subsequent blank media. Further, if illegal clones are manufactured that can calculate the media key, new blank media can change the media key block such that the clones can no longer calculate the correct media key. Authorized players, however, can decrypt the data to display it.
摘要:
A method for tracing traitor receivers in a broadcast encryption system. The method includes using a false key to encode plural subsets representing receivers in the system. The subsets are derived from a tree using a Subset-Cover system, and the traitor receiver is associated with one or more compromised keys that have been obtained by a potentially cloned pirate receiver. Using a clone of the pirate receiver, the identity of the traitor receiver is determined, or the pirate receiver clones are rendered useless for decrypting data using the compromised key by generating an appropriate set of subsets.
摘要:
An encryption key matrix has rows grouped into segments, with a set of one segment per column establishing a slot. Slots are assigned to device manufacturers, with the keys of the slots then being assigned to decryption devices made by the respective manufacturer. In generating the slots, the number “q” of segments in a column is first defined such that a predetermined maximum number of devices can be revoked devices (in that all the keys held by the device are revoked) while ensuring that a good device remains a functional device with a probability of at least (1−Q), wherein Q is a predefined device confidence. Once the number “q” of segments has been defined, the slots themselves are defined in a provably non-discriminatory fashion using an error-correcting code such as a Reed-Solomon code. With this invention, overlap between slots can be minimized to minimize the possibility that the key set of an innocent device might be inadvertently revoked when the keys in the slots of a “bad” manufacturer are revoked.