Systems and methods for privacy-preserving inventory matching are disclosed. In one embodiment, in an information processing apparatus comprising at least one computer processor, a method for inventory matching may include: (1) receiving, from each of a plurality of clients, a masked submission comprising an identification of at least one security to buy or sell and a desired quantity to buy or sell; (2) aggregating the masked submissions resulting in a sum of the desired quantities to buy or sell; (3) matching at least two of the clients to conduct a transaction based on aggregation and their respective masked submissions; and (4) conducing the transaction between the matched clients.

A method for evaluating data is based on a computational model, the computational model comprising model data, a training function and a prediction function. The method includes training the computational model by: receiving training data and training result data for training the computational model, and computing the model data from the training data and the training result data with the training function. The method includes predicting result data by: receiving field data for predicting result data; and computing the result data from the field data and the model data with the prediction function. The training data may be plaintext and the training result data may be encrypted with a homomorphic encryption algorithm, wherein the model data may be computed in encrypted form from the training data and the encrypted training result data with the training function. The field data may be plaintext, wherein the result data may be computed in encrypted form from the field data and the encrypted model data with the prediction function.

A system includes circuitry for rewriting blockchains in a non-tamper-evident or tamper-evident operation using a key secret held in portions by multiple individually untrusted parties. The blockchains may include a series of blocks secured by integrity codes that may prevent non-tamper-evident rewrites by non-trusted parties that are not in possession of the key secret or individually-untrusted parties in possession of only a portion of the key secret. In some cases, multiple individually-untrusted parties may combine their portions into the key secret. As a group, the multiple individually-untrusted parties may perform non-tamper-evident operation with respect to at least one integrity code within the blockchain.

Systems and methods for threshold authenticated encryption are provided. A collection of cryptographic devices may encrypt or decrypt a message, provided that a threshold number of those devices participate in the encryption process. One cryptographic device may generate a commitment message and transmit it to the other selected devices. Those devices may each perform a partial computation using the commitment message, and transmit the partial computations back to the encrypting or decrypting device. The encrypting or decrypting device may use those partial computations to produce a cryptographic key, which may then be used to encrypt or decrypt the message.

Methods, systems, and devices for communications are described. A device or a group of devices may generate data. The group of devices may receive a group profile from a node that identifies the devices to be included, and the group profile may include a function to be evaluated at each of the devices. The node may also provision evaluation parameters which may allow the device to provide authenticated aggregate data to a requesting third party, without sharing the data between the devices, thus concurrently maintaining individual data privacy and data provenance.

System and method for digitally signing messages using multi-party computation.

According to an aspect, there is provided a computer-implemented method of operating a first node. The first node has an algorithm for evaluating input data from another node, with the input data having a plurality of different attributes. The method comprises receiving, from a second node, a proposal for the evaluation of a first set of input data by the algorithm; estimating the performance of the algorithm in evaluating the first set of input data based on the proposal; and outputting, to the second node, an indication of the estimated performance of the algorithm. A corresponding first node is also provided.

A first component determines encrypted data representing an event and encrypted threshold data corresponding to an outlier of the event. The first system may process the data using, for example, one or more composite integers, and may send the result to a second system. This second system may subtract the data to determine of the encrypted data is greater than, less than, or equal to the encrypted threshold. If so, the second system may determine that the encrypted data corresponds to an outlier of the data. The second system may send an indication of this determination to a third system.

A system and method for training a decision tree are disclosed. A method includes publishing, by a first party, a first set of nominated cut-off values at a current node of a decision tree to be trained, computing a first respective impurity value for the first set of nominated cut-off values at the current node, creating first respective n shares of the first respective impurity value, transmitting, from the first party and so a second party, one of the first respective n shares of the first respective impurity value, receiving from the second party one of a second respective n shares of the second respective impurity value, adding a group of impurity values to yield a combined impurity value based on the one of the first respective n shares and the one of the second respective n shares and determining, based on the combined impurity value, a best threshold.

Systems and methods for homomorphic encryption-based triggering are disclosed. According to an embodiment, a method for homomorphic encryption-based triggering may include: (1) receiving, by a backend computer program executed by a backend electronic device and from a computer program for a client, a trigger condition for an event, the trigger condition encrypted with a public key for an organization and an action to be executed in response to the trigger condition being met; (2) receiving, by the backend computer program, a stream of data encrypted with the public key; (3) comparing, by the backend computer program, the encrypted trigger condition to the encrypted stream of data; (4) determining, by the backend computer program, that the trigger condition is met; and (5) executing, by the backend computer program, the action associated with the trigger condition.