Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.

Abstract: In one embodiment, a first signature template is received, the first signature template being one of a signature template of a first message or a null template, the first signature template comprising at least the following fields: an aggregation depth field, a message identifier, one of the first message or a result of applying a one way hash function to the first message, a bit vector, an aggregated square random integer mod N, a signature of the first message. A second signature template is created based on the first signature template, the second signature template created as follows: increment the aggregation depth of the first signature template, determine a unique message identifier for a second message, determine a second bit vector, determine an second aggregated square random integer mod N, and calculate a new signature for the second message. Related methods, apparatus, and systems are also disclosed.

Abstract: In one embodiment, a method, system, and apparatus are described, the method, system, and apparatus including generating metadata to be associated with each block of a series of blocks, the generating including, except for an initial block, receiving: a first block, including a signed block, and a second block to be signed, retrieving a first value including a square of a random number, R?2, multiplying R?2 by a nonce, r, and setting r·R?2 to be a square of a first random number, denoted R2, for the second block, retrieving a second value from the first block, the second value including K-bit vector, E?, determining a bit string value of the second block, M, computing E=hash(R2?M?E?), and determining a signature, Sig, for the second block by calculating Sig=r Sig? SE-E?. Related methods, systems, and apparatuses are also described.

Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.

Abstract: In one embodiment, a method, system, and apparatus are described, the method, system, and apparatus including generating metadata to be associated with each block of a series of blocks, the generating including, except for an initial block, receiving: a first block, including a signed block, and a second block to be signed, retrieving a first value including a square of a random number, R?2, multiplying R?2 by a nonce, r, and setting r·R?2 to be a square of a first random number, denoted R2, for the second block, retrieving a second value from the first block, the second value including K-bit vector, E?, determining a bit string value of the second block, M, computing E=hash(R2?M?E?), and determining a signature, Sig, for the second block by calculating Sig=r Sig? SE-E?. Related methods, systems, and apparatuses are also described.

Abstract: One embodiment of the invention includes a method, including performing, a symmetric homomorphic encryption of a secret SA with a cryptographic key H as input yielding a homomorphic encryption result SA*, sending SA* for mathematical combination by at least one device with at least one secret SB yielding G*, the device A not having access to SB, the at least one device not having access to SA and not having access to H, receiving G*, performing a symmetric homomorphic decryption of data based on G* with H as input yielding a first decrypted output, determining a symmetric cryptographic key KA based on the first decrypted output for secure communication with a first device which is operationally connected to, or includes, a tamper resistant security system including SA and SB therein, securing data using KA yielding secured data, and sending the secured data to the first device.

Abstract: In one embodiment, a first signature template is received, the first signature template being one of a signature template of a first message or a null template, the first signature template comprising at least the following fields: an aggregation depth field, a message identifier, one of the first message or a result of applying a one way hash function to the first message, a bit vector, an aggregated square random integer mod N, a signature of the first message. A second signature template is created based on the first signature template, the second signature template created as follows: increment the aggregation depth of the first signature template, determine a unique message identifier for a second message, determine a second bit vector, determine an second aggregated square random integer mod N, and calculate a new signature for the second message. Related methods, apparatus, and systems are also disclosed.

Abstract: A method for facilitating multiple recordings via a single tuner includes isolating data packets associated with recording candidate media assets from at least two broadcast data streams, generating at least one broadcast recording data stream from a subset of the isolated data packets, broadcasting the at least one broadcast recording data stream in parallel with the at least two broadcast data streams, where the broadcast recording data stream is broadcast via at least one dedicated broadcast “recording” device, and the at least two broadcast data streams are broadcast via other broadcast devices, storing remaining data packets not included in the isolated data packets in broadband data segments, and transmitting the broadband data segments via an IP connection to facilitate reassembly of partially recorded the media assets, where the partially recorded media assets were recorded from the broadcast recording stream. Related methods and apparatus are also disclosed.

Abstract: One embodiment of the invention includes a method, including performing, a symmetric homomorphic encryption of a secret SA with a cryptographic key H as input yielding a homomorphic encryption result SA*, sending SA* for mathematical combination by at least one device with at least one secret SB yielding G*, the device A not having access to SB, the at least one device not having access to SA and not having access to H, receiving G*, performing a symmetric homomorphic decryption of data based on G* with H as input yielding a first decrypted output, determining a symmetric cryptographic key KA based on the first decrypted output for secure communication with a first device which is operationally connected to, or includes, a tamper resistant security system including SA and SB therein, securing data using KA yielding secured data, and sending the secured data to the first device.

Abstract: In one embodiment, a method for reducing information leakage in order to counter side channel attacks against a secure execution environment is described, the method including receiving at the secure execution environment a first input comprising a key comprising a sequence of k input elements in a commutative ring, CR, receiving at the secure execution environment a second input comprising a text comprising a sequence of p input elements in the commutative ring, CR, defining an input INP comprising a sequence of j input elements, wherein INP comprises either one or both of the first input or the second input, performing one of a matrix randomization operation or a polynomial randomization operation on the inputs, and producing a randomized output.

Abstract: A method for distributing encrypted information includes; encrypting an item of information with a content key, distributing the item of encrypted information over a wide-area communication network to client devices, generating a plurality of key-shares from the content key, where the generating includes requiring a predetermined number of no less than two of the key-shares to reconstruct the content key, distributing respective key-shares to the client devices, where the distributing includes distributing less than the predetermined number of key-shares to the client devices, receiving a report over the wide-area communication network from a first client device indicating that while a second client device was disconnected from the wide-area communication network, the second client device requested and received at least one of the key-shares from the first client device, and determining that the second client device accessed the item of information and recording a delivery of the item of information.

Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.

Abstract: In one embodiment, a method for reducing information leakage in order to counter side channel attacks against a secure execution environment is described, the method including receiving at the secure execution environment a first input comprising a key comprising a sequence of k input elements in a commutative ring, CR, receiving at the secure execution environment a second input comprising a text comprising a sequence of p input elements in the commutative ring, CR, defining an input INP comprising a sequence of j input elements, wherein INP comprises either one or both of the first input or the second input, performing one of a matrix randomization operation or a polynomial randomization operation on the inputs, and producing a randomized output.

Abstract: A fully homomorphic method and system for randomizing an input, wherein all computations are over a commutative ring is described. Equivalent methods for performing the randomization using matrices and polynomials are detailed, as well as ways to mix the matrix and polynomial functions. Addition, multiplication, and division of the matrix and polynomial functions is further described. By performing computations of the functions modulo N over a ring ZN, the functions are usable as encryption functions. The method and system can also be used for verifying that a returned result of a calculation performed by a third party is valid for any of the calculations described herein. Related methods, systems, and apparatus are also described.

Abstract: A cryptographic method, comprising receiving a public key belonging to a message recipient having a private key corresponding to the public key, selecting a numerical seed, having a first entropy, using the numerical seed and the public key, generating key recovery information having a second entropy, which is less than the first entropy, and generating a message key having a third entropy, which is less than the first entropy, encrypting a message using the message key, and transmitting the encrypted message and the key recovery information to the message recipient, whereby the recipient reconstructs the message key using the key recovery information and the private key and decrypts the encrypted message using the reconstructed message key. Related systems and methods are also included.

Abstract: A system including a memory having regions including a first and second region, the first region being different from the second region, and a digital rights management engine to receive a plurality of ciphertext cipher blocks, decrypt the ciphertext cipher blocks yielding plaintext cipher blocks, output the plaintext cipher blocks to the first region of the memory over a period of time, provide a plurality of decoy cipher blocks in addition to the plaintext cipher blocks, the decoy cipher blocks having a pattern in which: a first one of the decoy cipher blocks consists of data, and a second one of the decoy cipher blocks consists of data which is the same as the data of the first one of the decoy cipher blocks, and output the decoy cipher blocks to the second region of the memory during the period of time. Related apparatus and methods are also included.

Abstract: A computer-implemented letter-based method of encoding a length-significant portion of natural language text to generate a letter-based fingerprint of the text portion, the method including detecting letter-based locations of occurrences of pre-determined single-letter and/or multi-letter pattern(s) within the length-significant portion, the detecting being carried out such that at least some occurrences are detected in a word-boundary independent manner that does not depend on locations of word-word boundaries, for a pattern occurrence letter-position signal which describes letter positions of the occurrences of the patterns within the text portion, computing frequency-dependent absolute or relative magnitudes of signal strength for a plurality of frequencies, the computed magnitudes representing letter-based frequencies of the pattern occurrences within the natural language text portion, and storing the computed signal strength magnitudes at the plurality of frequencies, the generated fingerprint comprising

Abstract: A cryptographic method, including generating, using a meta-secret, a first plurality of cryptographic keys, each cryptographic key associated with a respective key identifier, creating, using the meta-secret, a second plurality of sets of secret-shares, which are capable, by combining all the secrets-shares in any one of the sets together with the respective key identifier, of generating the associated cryptographic key, and performing cryptographic operations using the cryptographic keys. Related methods and apparatus are also included.

Abstract: A fully homomorphic method and system for randomizing an input, wherein all computations are over a commutative ring is described. Equivalent methods for performing the randomization using matrices and polynomials are detailed, as well as ways to mix the matrix and polynomial functions. Addition, multiplication, and division of the matrix and polynomial functions is further described. By performing computations of the functions modulo N over a ring ZN, the functions are usable as encryption functions. The method and system can also be used for verifying that a returned result of a calculation performed by a third party is valid for any of the calculations described herein. Related methods, systems, and apparatus are also described.

Abstract: A method for facilitating multiple recordings via a single tuner includes isolating data packets associated with recording candidate media assets from at least two broadcast data streams, generating at least one broadcast recording data stream from a subset of the isolated data packets, broadcasting the at least one broadcast recording data stream in parallel with the at least two broadcast data streams, where the broadcast recording data stream is broadcast via at least one dedicated broadcast “recording” device, and the at least two broadcast data streams are broadcast via other broadcast devices, storing remaining data packets not included in the isolated data packets in broadband data segments, and transmitting the broadband data segments via an IP connection to facilitate reassembly of partially recorded the media assets, where the partially recorded media assets were recorded from the broadcast recording stream. Related methods and apparatus are also disclosed.