Abstract: User rating data may be received at a correlation engine through a network. The user rating data may include ratings generated by a plurality of users for a plurality of items. Correlation data may be generated from the received user rating data by the correlation engine. The correlation data may identify correlations between the items based on the user generated ratings. Noise may be generated by the correlation engine, and the generated noise may be added to the generated correlation data by the correlation engine to provide differential privacy protection to the user rating data.

Abstract: User rating data may be received at a correlation engine through a network. The user rating data may include ratings generated by a plurality of users for a plurality of items. Correlation data may be generated from the received user rating data by the correlation engine. The correlation data may identify correlations between the items based on the user generated ratings. Noise may be generated by the correlation engine, and the generated noise may be added to the generated correlation data by the correlation engine to provide differential privacy protection to the user rating data.

Abstract: An addition chain is first generated, and then an integer x is derived from it. Doubling and star steps may be implemented in the addition chain. This approach eliminates the computationally expensive step of generating the addition chain from an exponent, and therefore can greatly reduce the computation time of the modular exponentiation.

Abstract: A system and method for verifying messages. The method may include the steps of receiving an inbound message and characterizing the inbound message by analyzing a latent cryptographic identifier in the inbound message. The identifier is generated by a recognized message system, which may be the receiving system itself, for an outbound message. Characterizing may involve detecting if the latent cryptographic identifier is present and determining if the cryptographic identifier is valid. The step of determining can be performed using symmetric or asymmetric methods of verifying the authenticity of the message.

Abstract: Techniques are disclosed to limit short-term correlations associated with outputs of stream cipher keystream generators. Output values of a generator are paired such that the paired outputs are sufficiently far apart to be considered independent. In one described implementation, a method includes sequentially storing a plurality of results provided by a stream cipher output rule in a first, second, and third storage units. A pairing function pairs individual values from the first and third storage units that are at least a threshold value apart. Upon reaching the threshold value of the output rule results, the contents of the first, second, and third storage units are rotated serially.

Abstract: A message is hashed with a first hash function to generate a first hashed message, and then the first hashed message is hashed with a second hash function to generate a second hashed message. The second hashed message is then signed. The first hash function may be a domain extender, such as a TCR (target-collision resistant) hash. The second hash function may be a random oracle. The second hash function may be slower than the first hash function. A signature scheme such as DSA, PSS-RSA, or Cramer-Shoup may be used.

Abstract: Systems and methods are provided for obscuring an amount of a resource used to process an item. In general, contemplated techniques comprise assigning a maximum allowable amount of the resource for processing a sub-part of the item. If the maximum allowable amount of the resource is reached, processing the sub-part may be terminated. Once all sub-parts are processed, a noisy quantity of the resource that was consumed in processing the item may be released. The noisy quantity is determined by adding a positive amount of the resource, combined with a noise value, to an actual quantity of the resource that was consumed.

Abstract: An addition chain is first generated, and then an integer x is derived from it. Doubling and star steps may be implemented in the addition chain. This approach eliminates the computationally expensive step of generating the addition chain from an exponent, and therefore can greatly reduce the computation time of the modular exponentiation.

Abstract: Techniques are disclosed to limit short-term correlations associated with outputs of stream cipher keystream generators. Output values of a generator are paired such that the paired outputs are sufficiently far apart to be considered independent. In one described implementation, a method includes sequentially storing a plurality of results provided by a stream cipher output rule in a first, second, and third storage units. A pairing function pairs individual values from the first and third storage units that are at least a threshold value apart. Upon reaching the threshold value of the output rule results, the contents of the first, second, and third storage units are rotated serially.