In some examples, in response to a request from a client device for information relating to a transaction stored by a blockchain, a system identifies, using information stored in a distributed storage system that stores data for the blockchain, multiple data owner entities from which permissions are to be obtained for access of the information, and determines an authorization requirement for the information based on a smart contract. The system sends authorization information based on the authorization requirement to trigger a retrieval of authorization tokens from the identified data owner entities for access of the information, and sends the information to the client device in response to receiving the authorization tokens.

A diamond asset comprising one or more diamonds and an encryption chip is used to asset-back a cryptographic token that can be used to conduct transactions. The cryptographic token is written to a blockchain using a smart contract that is configured to enable a transaction associated with the token in response to two or more of: a signature by the encryption chip, a signature by the owner of the diamond asset, and a validation of a visual layout of the diamond asset.

A user authentication method performed by an authentication management server constituting a block chain network with a target device may comprise receiving, from the target device, a transaction including authentication information of a user and a unique value of the target device; determining a token of the user stored in a smart contract based on the authentication information; and authenticating the user based on validity information of the token, ownership information of the token, and the transaction.

A system and method is disclosed for assuring that networked communications between parties playing a game on a network (e.g., the Internet) are not tampered with by either of the parties for illicitly gaining an advantage over the other party. An initial sequence of tokens (e.g., card representations) for playing the game are doubly encrypted using an encryption key from each of the parties. Accordingly, during play of the game neither party can modify the initial sequence of game tokens during the game. At termination of the game, at least one of the parties can fully decrypt the initial sequence of tokens, and thereby, if desired, compare the played token sequence with the corresponding the initial token sequence.

A method and system for determining whether a consensus has been achieved for adding a block to a distributed ledger. The system receives a candidate block to add to the distributed ledger and receives block approvals of approving participants for the candidate block. The system calculates a total block approval stake that the approving participants have in the distributed ledger. The system identifies a total stake that participants have in the distributed ledger. When the total block approval stake is at least a threshold fraction of the total skate, the system indicates that the consensus has been achieved for adding the candidate block to the distributed ledger.

A system and method are disclosed for the collection and aggregation of data from contributing members of a community, such as health-related, personal, genomic, medical, and other data of interest for individuals and populations. Contributors become members of a community upon creation of an account and providing of data or files. The data is received and processed, such as to analyze, structure, perform quality control, and curate the data. Value or shares in one or more community databases are computed and attributed to each contributing member. The data is controlled to avoid identification or personalization. Steps are taken to determine incompleteness and incorrectness of the data, and the data may be improved or completed automatically, based upon interaction with members, additional contributions of data, and so forth.

A personal blockchain is generated as a cloud-based software service in a blockchain environment. The personal blockchain immutably archives usage of any device, perhaps as requested by a user. However, some of the usage may be authorized for public disclosure, while other usage may be designated as private and restricted from public disclosure. The public disclosure may permit public ledgering by still other blockchains, thus providing two-way public/private ledgering for improved record keeping. Private usage, though, may only be documented by the personal blockchain.

[Object] The object is to present a technical solution for a bank to disclose information on a deposit account directly to a third party. [Solution Means] The owner of a virtual currency address or real-currency deposit account provides a disclosure key to a disclosee (third party). The third party accesses a disclosure server 6 by operating a disclosee terminal 7, and transmits a disclosure request with the disclosure key. The disclosure server 6 accesses to an opener bank server 1, 8, acquires the virtual currency address owner information or the instant real-currency deposit account balance information, transmits it to the disclosee terminal 7, and make it browsable on the disclosee terminal 7.

Disclosed herein are methods, systems, and apparatus for processing blockchain-based guarantee information. One of the methods includes receiving a first cyphertext of a first digital document specifying a guarantee from a first computing device associated with at least a first guarantor and one or more zero-knowledge proofs (ZKPs) related to one or more values associated with the guarantee, and the first digital document specifies one or more predetermined conditions of executing the guarantee; verifying that the one or more ZKPs are correct; storing the first cyphertext to a blockchain based on performing a consensus algorithm; receiving a first message from a second computing device associated with a beneficiary or a representative of the beneficiary.

A blockchain value transfer method including receiving a transfer request, executing a first smart contract function to perform data analytics on the transfer request and a second smart contract function to implement a security response responsive to compliance with a security criterion, and recording a result of execution of the second smart contract function to at least one of a relational database, a non-relational database, and an analytics service.