Abstract: A learning device includes an acquisition unit and a conversion unit. The acquisition unit inputs thereto, for each class, an output of a learner for each class received from another learning device and an output of a learner for each class trained by the own device, and acquires a given output for each class. The conversion unit performs, for each class, a conversion process to express a probability with respect to the given output for each class acquired by the acquisition unit.

Abstract: A server device includes an acquisition unit that acquires, from each of a plurality of client devices, information representing a value of a node constituting a decision tree, the information being determined based on the learning data held by the own device of each client device, and a determination unit that determines the value of the node constituting the decision tree by integrating the acquired results. The decision tree is learned by determination of the value of each node constituting the decision tree by the determination unit.

Abstract: Provided is a technique to prevent an attribute inference attack against a federated learning model. An information processing apparatus (2) includes: a detection section (21) that detects, as an outlier, an output value which falls outside a normal range in terms of magnitude of a value among output values of a decision tree which is undergoing federated learning; and a determination section (22) that determines, in a case where the outlier has been detected, that the decision tree has vulnerability to an attack to infer an attribute value included in training data which has been used to train the decision tree.

Abstract: A processing device includes an acquisition unit and a specifying unit. The acquisition unit acquires, from a decision tree that is a learned model and includes a plurality of nodes, score information representing a value according to the number of pieces of data that fell to each of the nodes, among a plurality of pieces of training data used for training of the decision tree. The specifying unit specifies a possible range that the value of an unknown feature may take, on the basis of the score information acquired by the acquisition unit. The unknown feature is a part of the features included in the training data.

Abstract: A signature verification system 100 includes a signature apparatus 210 configured to sign data including a predetermined data block replaced with a chameleon hash value, using one or more public keys for changers authorized to change data, a changing apparatus 310 configured to receive the signed data, and to change a content of the predetermined data block of the signed data using a private key associated with any of the one or more public keys, and a verifying apparatus 410 configured to receive the signed data with the changed content of the predetermined data block, and to verify the signature using the one or more public keys for the changers.

Abstract: A signature verification system includes: a signature apparatus configured to sign a first chameleon hash value, an unmodifiable part of the data, and a second chameleon hash value of an entirety of the data; a changing apparatus configured to change a public key for the changers of the temporary delegator to a public key for changers of an actual delegator, using a private key for the changers; a delegator changing apparatus configured to change a modifiable part of the data, using a private key for the changers of the actual delegator; and a verifying apparatus configured to verify the signature using the public key for the changers and the public key for the changers of the actual delegator.

Abstract: A data delivery apparatus includes: a key generation unit that generates a pair of a first signature key and a first verification key; a publishing unit that publishes the first verification key to outside; an acquisition unit that acquires a second verification key published by a data requesting apparatus, a secret value table generation unit that generates a secret value table including a plurality of secret values and indices; a signing unit that signs data, which includes processing target data including at least a part of delivery target data and an index corresponding to a secret value that has been associated with the processing target data based on the secret value table, by using the first signature key; and a first transmitting unit that transmits the signed transmission data to the data requesting apparatus.

Abstract: An information processing apparatus (2) includes a storage unit (21) in a secure area (20), the storage unit being configured to store a first common key (211) and a first private key (212) assigned to a measuring apparatus (1), an acquiring unit (223) configured to acquire, from the measuring apparatus (1), communication data including measurement data measured by the measuring apparatus (1) and an authentication code generated for the measurement data using the first common key (211), an authentication unit (221) configured to authenticate, in the secure area (20).

Abstract: Provided is an encryption system that suppresses a communication cost from a key issuing system to a user and controls input to a function in the unit of data. The encryption system includes an encrypting apparatus, a signature apparatus, and a security execution apparatus. The encrypting apparatus generates pseudo-random numbers different for respective pieces of data, and encrypts the generated pseudo-random numbers together with the pieces of data. The signature apparatus regenerates the pseudo-random numbers used by the encrypting apparatus for encrypting the respective pieces of data, and generates control information for certifying validity of the pieces of the data from the regenerated pseudo-random numbers.

Abstract: An apparatus publishes the first verification key generated in a first secure area outside the apparatus, acquires a second verification key that is generated in a second secure area of a data requesting apparatus and published by the data requesting apparatus, signs, in the first secure area, in response to a data delivery request, delivery target data using the first signature key, transmits transmission data obtained through the signing to the data requesting apparatus, receives certification data from the data requesting apparatus, verifies a signature of the certification data using the second verification key, and transmits, when the signature of the certification data is successfully verified using the second verification key, the certification data to the data providing apparatus.

Abstract: A data management method is a data management method in a data distribution system that manages, by using a blockchain, a distribution of data provided by a data provider. The data management method includes: receiving a token that is included in a second transaction and that indicates a result of determination of “permitted”, after a first transaction is registered in the blockchain and after the second transaction is registered in the blockchain, the first transaction indicating a use request for the data by a data user, the second transaction including the token that indicates a result of determination by the data provider with respect to the use request indicated by the first transaction; and providing the data to the data user on condition that the token is received.

Abstract: In order to provide an electronic trading system contributing to providing fair trading, an electronic trading system includes a plurality of management servers, a participant terminal, and a trading management server. The plurality of management servers provide a first electronic bulletin board. The participant terminal writes bid data in the first electronic bulletin board. The trading management server acquires the written bid data, and uses the acquired bid data to execute trading through Zaraba method. The trading management server generates a public key and a private key. The participant terminal uses the public key generated by the trading management server to encrypt the bid data. The trading management server uses the private key to decrypt the encrypted bid data.

Abstract: A management apparatus is operated by one operating entity. The management apparatus includes: a storage unit that stores a policy information, which is associated with data provided by a data provider to another operating entity that is different from the one operating entity, and which defines a provision permission policy of the data provider for the data; an acquisition unit that refers to a log information in which a first hash value of one policy information is recorded and that obtains a policy information corresponding to the one policy information from the storage unit, the one policy information being associated with one data provided to a data user from the another operating entity; and a comparison unit that calculates a second hash value of the obtained policy information and that compares it with the first hash value.

Abstract: An information processing device, an information processing system, a member identification method, and a program capable of preventing a member that has created an anonymous electronic signature from being arbitrarily identified from this signature are provided. A disclosure device (3) includes: a receiver (6) configured to receive signature information, which is information that constitutes an anonymous electronic signature; an identification information generation unit (7) configured to generate identification information, which is information for identifying a member that has created the anonymous electronic signature, based on the signature information; a storage unit (8) configured to store the number of times the identification information is generated by the identification information generation unit (7); and a transmitter (9) configured to transmit the identification information.