Abstract: A storage medium storing an information management program that causes a computer to execute a process that includes acquiring a first cumulative consideration amount from a most upstream process in a plurality of processes included in a supply chain to a first process; generating a consideration amount commitment by concealing the first cumulative consideration amount by using a random number; registering the consideration amount commitment in a blockchain; generating a consideration amount proof that is a zero knowledge proof that proves validity of the second cumulative consideration amount without disclosing the second cumulative consideration amount; and notifying the second process of the second cumulative consideration amount, the random number, and the consideration amount proof.

Abstract: A storage medium storing a consideration distribution program that causes at least one computer to execute a process that includes performing verification of validity of a first transaction stored in a blockchain, the first transaction including a first cumulative consideration from a most upstream process of a supply chain to a certain process, the first transaction being locked in one step downstream process by using a hash value based on a certain random number; storing a second transaction in the blockchain when a result of the verification is valid, the second transaction including a second cumulative consideration from the most upstream process to one step upstream process, the second transaction being locked; acquiring the first cumulative consideration by unlocking the first transaction based on the certain random number; and sending the certain random number to the one step downstream process.

Abstract: A computer-readable medium storing a program for causing a computer to execute processing in one of stages of a supply chain, the processing including: obtaining, from an immediately upstream stage, a first cumulative value being from a most upstream stage to the immediately upstream stage and a first random number used to generate a first commitment obtained by concealing the first cumulative value; generating, based on the first random number, a link commitment obtained by concealing information indicating a relationship between the immediately upstream stage and the stage; calculating, based on the first cumulative value, a second cumulative value being from the most upstream stage to the stage; generating a proof indicating that the second cumulative value is calculated using the correct first cumulative value and that is a zero-knowledge proof based on the link commitment; and causing the link commitment and the proof to be recorded in a blockchain.

Abstract: A system including: a first information processing device configured to: transmit one or more certificates issued to a specific user; acquire one or more pieces of encrypted information each including identification information of a user, and encrypted with a public key of the user to whom the certificate is issued; generate one or more pieces of decryption information that respectively correspond to the one or more pieces of encrypted information by decrypting the one or more pieces of encrypted information; and transmit the one or more pieces of decryption information; and a second information processing device configured to: receive the one or more certificates and the one or more pieces of decryption information; and evaluate a submission status of the certificate by the specific user based on the number of one or more certificates and the number of pieces of decryption information including the identification information of the specific user.

Abstract: An unauthorized use detection system includes apparatuses and a hash chain that records, for each piece of data, a data structure that includes a hash value of entire data and hash values calculated with respect to a plurality of partial areas obtained from a specific procedure using the hash value of the entire data. One of the apparatuses reads out the data structure associated with the data of one of comparison targets from the hash chain. The apparatus calculates, regarding data of the other one of the comparison targets, hash values of the plurality of partial areas obtained from the specific procedure using the hash value of the entire data included in the read data structure. The apparatus compares the hash values of the plurality of partial areas included in the read data structure with the calculated hash values of the plurality of partial areas related to the other one.

Abstract: A data storage method including: acquiring first data indicating a production record of a transaction resource produced by a producer and second data indicating a consumption record of the transaction resource consumed by a consumer; generating proof information proving that a condition of consistency between the first data and the second data is satisfied regarding allocation of the transaction resource for the production record of the producer as a supplier of the transaction resource for the consumption record of the consumer; generating third data that includes the proof information and has a data size smaller than a total data size of the first data and the second data; and storing a transaction record that includes the third data and indicates that the transaction resource is consumed by the consumer, in a blockchain storing a transaction history of a supply right of the transaction resource produced by the producer.

Abstract: A knowledge proof method for a first information processing device managed by a prover to execute a process includes generating a ciphertext obtained by encrypting a certain value with a public key of a verifier; generating proof information that proves that the prover has a secret value by a non-interactive zero-knowledge proof, based on a first function and the first input value including the second input value and the public key, the first function including calculation represented by a second function whose calculation result is the certain value when the second input value is input and calculation in which the calculation result of the second function is encrypted with the public key, and the first input value; and transmitting knowledge proof information that includes the ciphertext and the proof information to an information processing device managed by the verifier, who has a private key that corresponds to the public key.

Abstract: A blockchain method generates data on a new blockchain by linking a new block to data on a blockchain including a plurality of blocks linked together each being a set of data containing given information. The blockchain method may further includes: in generating a second block following a first block included in the data on the blockchain, identifying, among branch blocks approved prior to the generating of the second block, one or more blocks capable of being approved in parallel with the first block, and generating and registering, in a memory, the second block following the first block and the one or more blocks capable of being approved in parallel with the first block.

Abstract: A non-transitory computer-readable storage medium storing a program that causes a first computer to execute a process, the process including, receiving an update request from a second computer, the update request including an identifier of data stored in a storage device, an arithmetic operator of a calculation for the data, and an argument value used for the calculation, the calculation being one of four arithmetic calculation and bit calculation, the data being stored in the storage device that denies an access from the second computer, executing the calculation for a value of the data based on the arithmetic operator and the argument value, the calculation executed by the first computer being limited to the four arithmetic calculation or the bit calculation, updating the value of the data to an output value of the executed calculation, and transmitting response information corresponding to the update request to the second computer.

Abstract: A determination method performed by a first apparatus corresponding to a first user, the determination method includes acquiring, from a second apparatus corresponding to a second user which is different from the first user, first aggregated information in which identification information for identifying each user having a specific relationship with each user having a specific relationship with the first user is summarized; acquiring, from the second apparatus, second aggregated information in which identification information for identifying each user having a specific relationship with the second user is summarized; identifying a result which indicates a specific relationship between the first user and the second user based on the acquired first aggregated information and the acquired second aggregated information; and outputting the identified result.

Abstract: An unauthorized use detection system includes apparatuses and a hash chain that records, for each piece of data, a data structure that includes a hash value of entire data and hash values calculated with respect to a plurality of partial areas obtained from a specific procedure using the hash value of the entire data. One of the apparatuses reads out the data structure associated with the data of one of comparison targets from the hash chain. The apparatus calculates, regarding data of the other one of the comparison targets, hash values of the plurality of partial areas obtained from the specific procedure using the hash value of the entire data included in the read data structure. The apparatus compares the hash values of the plurality of partial areas included in the read data structure with the calculated hash values of the plurality of partial areas related to the other one.

Abstract: A blockchain method generates data on a new blockchain by linking a new block to data on a blockchain including a plurality of blocks linked together each being a set of data containing given information. The blockchain method may further includes: in generating a second block following a first block included in the data on the blockchain, identifying, among branch blocks approved prior to the generating of the second block, one or more blocks capable of being approved in parallel with the first block, and generating and registering, in a memory, the second block following the first block and the one or more blocks capable of being approved in parallel with the first block.

Abstract: A non-transitory computer-readable storage medium storing a program that causes a first computer to execute a process, the process including, receiving an update request from a second computer, the update request including an identifier of data stored in a storage device, an arithmetic operator of a calculation for the data, and an argument value used for the calculation, the calculation being one of four arithmetic calculation and bit calculation, the data being stored in the storage device that denies an access from the second computer, executing the calculation for a value of the data based on the arithmetic operator and the argument value, the calculation executed by the first computer being limited to the four arithmetic calculation or the bit calculation, updating the value of the data to an output value of the executed calculation, and transmitting response information corresponding to the update request to the second computer.

Abstract: A storage system includes a first information processor, a second information processor, and a superordinate device. The first information processor includes a first memory device that stores therein the data, a difference generator that generates difference data representing a difference between updating data received from the superordinate device and the data stored in the first memory device before updating, a second memory device stores therein the generated difference data, and a data transmitter that transmits the stored difference data to the second information processor. The second information processor includes a third memory device that stores therein the parity, a data receiver that receives the difference data transmitted from the data transmitter, and a parity difference applier that generates a post-updating parity that is to be written into the third memory device by applying the received difference data to the stored parity before the updating.

Abstract: An information processing device includes: a memory; and a processor coupled to the memory and the processor configured to: generate compressed data, in sets of a prescribed size, in respect of one set of object data, in accordance with each of a plurality of compression methods; and select compressed data of the compression method which has completed compression of the object data first, among the plurality of compression methods.

Abstract: An information processing device includes: a memory; and a processor coupled to the memory and the processor configured to: generate compressed data, in sets of a prescribed size, in respect of one set of object data, in accordance with each of a plurality of compression methods; and select compressed data of the compression method which has completed compression of the object data first, among the plurality of compression methods.

Abstract: A storage system includes an information processing apparatus and plural storage nodes. A replication unit replicates plural data elements respectively stored in plural data regions of one of the plural storage nodes, and stores replicated data elements respectively in plural data regions of each of the other storage nodes. A parity generation unit generates a parity corresponding to the data elements respectively stored in the plural data regions, and stores the parity in the parity region, for each of the storage nodes. The data selection unit selects one or more data regions that hold data elements, from among the plural data regions, and releases one or more non-selected data regions, for each of the storage nodes, so as to reduce a multiplicity of the data elements respectively stored in the plural data regions of each of the plural storage nodes.

Abstract: A storage control device includes a processor. The processor is configured to acquire, when a first fault has occurred in a first storage device, first storage data to be used in recovery of the first storage device from a plurality of first storage control devices. The processor is configured to derive, when a second fault has occurred in a second storage device controlled by a second storage control device, first processed data from the first storage data. The first processed data is to be used in recovery of the second storage device. The processor is configured to notify the second storage control device of the first processed data.

Abstract: A parity-layout generating method, includes: creating a first local parity layout with a first calculation range for calculating local parity; creating a second local parity layout with a second calculation range for calculating local parity, a length of the second calculation range being different from a length of the first calculation range; and creating, by a computer, a third local parity layout with the first calculation range and the second calculation range by combining the first local parity layout and the second local parity layout.

Abstract: A storage system includes a first information processor, a second information processor, and a superorainate device. The first information processor includes a first memory device that stores therein the data, a difference generator that generates difference data representing a difference between updating data received from the superordinate device and the data stored in the first memory device before updating, a second memory device stores therein the generated difference data, and a data transmitter that transmits the stored difference data to the second information processor. The second information processor includes a third memory device that stores therein the parity, a data receiver that receives the difference data transmitted from the data transmitter, and a parity difference applier that generates a post-updating parity that is to be written into the third memory device by applying the received difference data to the stored parity before the updating.