Source identification for unauthorized copies of content
First Claim
1. A computer-implemented method, comprising:
- obtaining license information that specifies a set of key derivation parameters;
obtaining encrypted data that comprise multiple copies of a portion of the encrypted data, each copy of the multiple copies being decryptable using a different key and being distinguishable from at least one other copy of the multiple copies;
using a one-way function to derive, based at least in part on the set of key derivation parameters and a first key, a second key to result in a derived second key, the set of key derivation parameters comprises multiple key derivation parameters and specifies an order in which to use the multiple key derivation parameters to obtain the derived second key;
using the derived second key to decrypt the portion to result in a decrypted portion; and
providing the decrypted portion.
1 Assignment
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Accused Products
Abstract
Systems and methods for authentication generate keys from secret credentials shared between authenticating parties and authenticators. Generation of the keys may involve utilizing specialized information in the form of parameters that are used to specialize keys. Keys and/or information derived from keys held by multiple authorities may be used to generate other keys such that signatures requiring such keys and/or information can be verified without access to the keys. Keys may also be derived to form a hierarchy of keys that are distributed such that a key holder'"'"'s ability to decrypt data depends on the key'"'"'s position in the hierarchy relative to the position of a key used to encrypt the data. Key hierarchies may also be used to distribute key sets to content processing devices to enable the devices to decrypt content such that sources or potential sources of unauthorized content are identifiable from the decrypted content.
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Citations
18 Claims
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1. A computer-implemented method, comprising:
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obtaining license information that specifies a set of key derivation parameters; obtaining encrypted data that comprise multiple copies of a portion of the encrypted data, each copy of the multiple copies being decryptable using a different key and being distinguishable from at least one other copy of the multiple copies; using a one-way function to derive, based at least in part on the set of key derivation parameters and a first key, a second key to result in a derived second key, the set of key derivation parameters comprises multiple key derivation parameters and specifies an order in which to use the multiple key derivation parameters to obtain the derived second key; using the derived second key to decrypt the portion to result in a decrypted portion; and providing the decrypted portion. - View Dependent Claims (2, 3, 4, 5)
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6. A system, comprising:
memory to store instructions that, if executed by one or more processors of the system, cause the system to; obtain an encrypted data set that includes multiple copies of a portion of the data set that are decryptable using different keys; use a one-way function to generate, based at least in part on a first key and a set of key derivation parameters for the encrypted data set, a different key to result in a generated different key, the set of key derivation parameters comprises multiple key derivation parameters and specifies an order in which to use the multiple key derivation parameters to obtain the generated different key; decrypt, using the generated different key, a copy of the multiple copies to result in a decrypted copy; and provide the decrypted copy. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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14. A non-transitory computer-readable storage medium having stored thereon instructions executable by one or more processors of an information processing system to cause the information processing system to at least:
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use a one-way function to derive, based at least in part on a key and a set of key derivation parameters obtained from license information for a set of data, a different key to result in a derived different key, the license information orders the set of key derivation parameters and an ordering of a subset of the key derivation parameters indicates an order in which the parameters are to be used to derive the different key; decrypt, using the derived different key, a copy selected from multiple copies of a portion of a subset of the set of data; and provide the decrypted copy. - View Dependent Claims (15, 16, 17, 18)
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Specification