Abstract: A similarity calculation system calculating a distance between a first vector stored in a similarity calculation apparatus and a second vector entered from an input terminal wherein the similarity calculation apparatus transmits to the input terminal a ciphertext of each element of the first vector and a weighted distance table with respect to combinations of possible values of the elements of the first vector and the second vector, and the input terminal refers to the weighted distance table to calculate a ciphertext of element distances for all combinations of the value of a single element of the second vector and possible values of elements of the first vector, calculates the ciphertexts of the sum of the element distances for each element of the second vector using additive homomorphic encryption, and transmits the ciphertext of the sum to the similarity calculation apparatus.

Abstract: An advertisement distribution guarantee apparatus 10, includes; a viewing certificate generation unit 11 that causes a viewer terminal to generate a viewing certificate for a viewed advertisement content on condition that the advertisement content is viewed on the viewer terminal; a viewing certificate recording unit 12 that makes the generated viewing certificate visible to the advertiser of the advertisement content and causes the viewer terminal to record the generated viewing certificate in a blockchain database.

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: 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: This ticket validity confirmation device prepares certificate data that is associated with one ticket and that comprises a set of certificate preparation information and certificate verification information, then stores the certificate verification information in a storage device, and transmits the certificate preparation information to a ticket information processing device. The ticket information processing device prepares a ticket validity certificate on the basis of the certificate preparation information, and transmits the ticket validity certificate to the ticket validity confirmation device. The ticket validity confirmation device verifies the ticket validity certificate on the basis of the certificate verification information stored in the storage device.

Abstract: The present invention enables payment proxy for a virtual currency in a decentralized virtual currency system. A payment proxy device includes: first generation unit for generating a first transaction by use of a balance of a proxy in response to a request from a payment source, the first transaction including first destination information which includes, as destinations, an account of the proxy, an account of the payment source, and payment destination information representing a payment destination, and approval information of the proxy, and being a transaction indicating trading of a virtual currency; acquisition unit for acquiring payment destination identification information transmitted by a payment destination as an evidence of receipt of money and intended for identifying the payment destination; and second generation unit for generating a second transaction using the first transaction as a balance, and a fourth transaction using, as a balance, a third transaction generated by the payment source.

Abstract: The present invention enables a virtual currency payment to be processed by an agent in a decentralized virtual currency system. A payment agent device 10 comprises: a first generation unit 110 which, in response to a request from a payer, generates a first transaction that includes first destination information indicating at least an agent and a payee as destinations, and that also includes first amount information and approval information about the agent; and a second generation unit 120 which generates a second transaction on the basis of approval information about the payee transmitted from the payee, and using the first transaction as an outstanding amount, wherein the second transaction includes second destination information indicating the payee as a destination, and also includes second amount information, the approval information about the agent, and the approval information about the payee.