There is provided a transaction system that includes a plurality of computing nodes that are mutually interconnected via a data communication network to exchange encrypted data therebetween. The transaction system employs a blockchain whose entries are recorded in a ledger. A directed acyclic graph (DAG) is utilized for defining relationships between blocks of the blockchain. The DAG comprises a plurality of proposed solutions to problems posed in the one or more smart contracts. Each of the one or more smart contracts includes machine-readable elements including at least one of: a data specification, an initial mining algorithm, an objective function for scoring the plurality of proposed solutions. The transaction system operates to cause the DAG to store temporary data and/or extended algorithm code used during an execution of a given transaction, wherein the temporary data and/or extended algorithm code stored in the DAG is to be removed once the execution of the given transaction is complete, further wherein the temporary data and/or extended algorithm code stored in the DAG is to be modified in response to new solutions arising during operation of the transaction system. The transaction system operates to accommodate a given smart contract defining a problem that is to be solved, giving a plurality of parties of the transaction system an opportunity to receive consideration when the problem is solved, and wherein the consideration is a quantity representing at least one of: an access to data storage, an access to data memory, an access to data communication system bandwidth, access to data communication channels or ports, data processor energy use, data processor energy dissipation, an access time taken by data processing resources during transactions, heat generation in computing hardware, cooling energy applied to computing hardware or any other measure associated with one or more CPU cycles.

A control method includes: receiving first transaction data related to a sign-up for service and storing the first transaction data received into the distributed ledger included in each of the plurality of servers, the service offering, if a goal condition predetermined for the service is satisfied, a token to a participant that is a user who signs up for the service; storing, into the distributed ledger, second transaction data indicating that the user is offered the token predetermined for the service, if it is determined that the goal condition is satisfied; and storing, into the distributed ledger, third transaction data indicating that the user is offered a deposit that is a temporary token predetermined for the service, at a predetermined timing included in a period from the storing of the first transaction data into the distributed ledger until when determination of whether the goal condition is satisfied is performed.

Examples for enabling off-network transactions to be performed and securely managed are provided. An example system may include a data network, a digital ledger server, a blockchain platform, smart payment devices, and point of sale devices. Each respective point of sale device and each respective smart device may be operable to perform an off-network transaction, and store information related to the transaction in a digital ledger coupled to each respective device. When a transaction is executed between a POS device and a smart payment device, the POS device and smart payment device exchange a record of all off-network transactions that each respective device has executed since the last time a connection was made to the data network. When a network connection is established for each device, the respective information stored in the digital ledger is uploaded to the blockchain platform for storage and the digital ledger server for transaction resolution.

Described processes include: determining portions of instances of a cryptographic token to be allocated to record providers, like providers of an asset indicated by a record, wherein: the portions are determined based on network effects associated with the records the record provider supplied on performance of a computer-implemented network in which both record providers and record consumers participate, patterns indicative of inorganic consumption may be determined from one or more of interactions of individual consumers, interactions of collections of consumers, or consumer interactions in the aggregate for a given provider or record; and the effects on network performance are adjusted responsive to designation of one or more entities as exhibiting inauthentic behavior; and appending to a distributed ledger, records indicating the respective portions, and adjustments, are allocated to record providers.

Systems and methods described herein include first and second devices including one or more processors and memory, the first device being configured to purchase one or more certificates by a first process via one or more blockchain transactions. The second device may be in communication with the first device, and may be redeem the one or more certificates received by a second process via one or more blockchain transactions. The second device may exchange one or more codes to designate the one or more certificates as used on the first device. The system may include one or more servers in communication with the second device, and may be automatically generate a message containing updated redemption information of the one or more certificates when the updated redemption information has been stored in one or more databases, which may be in communication with the one or more servers.

One embodiment of the invention is directed to a method that utilizes a mapping between a blockchain address and a payment credential. In some embodiments, the mapping may have been previously generated based on blockchain data (e.g., one or more blockchain tokens) associated with a blockchain address and a previously provided set of conditions. An authorization request message is later received that includes the payment credential. The blockchain address may be retrieved from the mapping and it may be determined whether the set of conditions have been met. One or more operations may be executed based on determining the set of conditions have been met.

Disclosed is a curable composition with enhanced curing time at ambient temperatures, the curable composition including (a) a resin, e.g., 4,4′-isopropylidenediphenol-epichlorohydrin copolymer and (b) one or more curing agents, wherein a ratio of a weight percentage of the resin to a weight percentage of the curing agent or curing agents is from about 12:1 to about 15:1. Also disclosed is a method of curing a cured-in-place liner, wherein the cured-in-place liner contains the above curable composition.

Various embodiments of the disclosure relate to a payment method using biometric authentication, and an electronic device thereof. The electronic device includes a communication module configured to provide communication with a server, a processor operatively coupled to the communication module, and a memory operatively coupled to the processor and configured to store biometric information. The memory may store instructions, when executed, causing the processor to, when registered for a first time use, generate a parameter for biometric authentication verification and an encrypted password for password authentication verification and transmit the generated parameter and password to the server, in order to register, with the server, biometric authentication information for biometric authentication verification and a password for password authentication, when a payment is made, use at least one of the biometric authentication and the password authentication to authenticate a user, and when it is necessary to change the biometric authentication information registered with the server, register new biometric authentication information with the server in the process of the payment.

The techniques herein are directed generally to a “zero-knowledge” data management network. Users are able to share verifiable proof of data and/or identity information, and businesses are able to request, consume, and act on the data—all without a data storage server or those businesses ever seeing or having access to the raw sensitive information (where server-stored data is viewable only by the intended recipients, which may even be selected after storage). In one embodiment, source data is encrypted with a source encryption key (e.g., source public key), with a rekeying key being an encrypting combination of a source decryption key (e.g., source private key) and a recipient's public key. Without being able to decrypt the data, the storage server can use the rekeying key to re-encrypt the source data with the recipient's public key, to then be decrypted only by the corresponding recipient using its private key, accordingly.

The present disclosure provides a method and a device for blockchain transaction tracing. The method includes acquiring information of a transaction-to-be-traced, where the information of the transaction-to-be-traced includes an input value of the transaction-to-be-traced; according to the input value of the transaction-to-be-traced and a Bloom filter corresponding to each block in a blockchain system, determining a leaf node of the transaction-to-be-traced, where the Bloom filter stores an output value of a transaction contained in each block; and according to the leaf node of the transaction-to-be-traced, generating a tracing path of the transaction-to-be-traced.