Exclusive ownership of data units, such as monetary units, is transferred by inputting a request from a transferor, to transfer to a transferee at least a designated one of the data units, said request including an identifier of the transferor, an identifier of the designated data unit, and an identifier of a transferee. The identifier of the transferor is verified and the absence of any other request to transfer the designated data unit is confirmed. A designation of ownership of the designated data unit is then changed from the transferor to the transferee in a ledger, which is comprised of a group of subledgers, each configured as a blockchain.

The invention provides a generic operating system for coordinating, controlling and/or influencing the activities of a device. The invention is implemented using a blockchain platform with which the operating system is arranged to interact. The blockchain may be the Bitcoin blockchain. In a preferred embodiment, the device is an Internet of Things (TOT) device. The invention provides a computer-implemented control system and corresponding method for controlling a device, the system comprising a device configured for wireless communication with a network and having an IP address and a public-private key cryptographic key pair associated with the device; a software-implemented control component arranged to monitor the state of a blockchain network and/or transmit blockchain Transactions to the blockchain network; and a set of instructions arranged for execution by the control component to control the functionality of the device. The control component is arranged to access the set of instructions from a stored location, which is separate to the device. The instructions may be stored in a Distributed Hash Table (DHT) and accessed for download and installation by the control component from the DHT as and when needed. The location of the DHT and/or instructions may be indicated or provided using metadata provided within a blockchain transaction. The set of instructions may be accessed by the control component using a look-up key, which is related to a cryptographic key pair. The control component is provided on or in the device, or in other embodiments can be provided in an off-device location and arranged for wireless communication with the device.

A method includes establishing an agreement between a first issuing server and a second issuing server regarding first exchange items to have an extended use. The method further includes establishing control of an exchange item of the first exchange items in accordance with a trust approach that includes the marketplace server utilizing a private key of a marketplace private/public key pair to generate a digital signature over a public key of the marketplace private/public key pair and exchange item information regarding the exchange item to produce a portion of a transactions blockchain. The method further includes transferring control of the exchange item to a user computing device. The method further includes receiving a request for use of the exchange item from a merchant server regarding a transaction by the user computing device and processing the request for use of the exchange item in accordance with an exchange item rule.

This application provides a decentralized electronic contract attestation platform, where the attestation platform is connected to a user client through a deposit thread and a forensic thread that are established with an existing electronic contract platform; the attestation platform includes a deposit unit and a forensic unit; the deposit unit is configured to verify transaction data of a deposit transaction initiated by the user client, and if the verification is passed, upload and store the transaction data on a chain; and the forensic unit is configured to obtain, based on a forensic request sent by the user client, transaction data that corresponds to the forensic request and is stored in a blockchain, and send the transaction data to the user client. According to this application, deposit and forensic operations of an electronic contract are correspondingly completed by using the established deposit thread and forensic thread. Managing the transaction data of a user by using the decentralized electronic contract attestation platform avoids a possibility that an existing platform may arbitrarily tamper with the transaction data of the deposit transaction of the user, and improves security of transaction information of the user.

This application discloses a transaction-based electronic contract deposit system, including an electronic contract platform and a blockchain deposit platform, the blockchain deposit platform including a plurality of deposit nodes that provide deposit services for the electronic contract platform. In this way, the following problem may be resolved: regarding an existing manner of storing an electronic contract in a centralized way, during a subsequent process of invoking electronic contract data, the stored electronic contract data becomes untrustworthy because the contract data is at a risk of being easily tampered with and forged.

Embodiments relate to methods, systems, devices, and computer readable medium for managing digital assets, such as cryptocurrencies and public key and private key pairs. The method includes identifying a public key or public address of a digital asset. The method includes identifying a public key of an authorized custodian of the digital asset. The method includes identifying a signed proof of management hash. The method includes determining whether an entity is the authorized custodian of the digital asset by generating an entity hash and comparing it to a first decrypted result. The first decrypted result is obtained by decrypting, using the public key of the authorized custodian, the signed proof of management hash. When the generated entity hash is determined to match the first decryption result, the method includes returning a confirmation that the entity is the authorized custodian of the digital asset.

Systems and methods for digital coin exchange. A digital coin platform receives a distribution request from an entity server comprising digital multimedia content associated with an entity. Digital coins are created responsive to the request. Each digital coin comprises a first coin associated with the entity and a second coin associated with consumers. The first and second coins are linked via linking information. The first coins are transferred to the entity server. A consumption request including the digital multimedia content is transmitted to a consumer device. Responsive to an indication that the content is at least partially consumed via the consumer device, one or more second coins are transferred to the consumer device. The digital coins and the transferred first and second coins are recorded. The transferred second coins permit the consumer device to perform transactions associated with the entity.

A method for conducting cryptocurrency transactions at an access device. The method includes initiating communication with an access device operated by a second user in a transaction between the first user and the second user, and then transmitting a request for transaction data to the access device. The method also includes receiving the transaction data comprising a transaction amount and a second cryptocurrency address from the access device from the access device, and signing, using a private cryptographic key, the first cryptocurrency address, the second cryptocurrency address, and the amount to create a signed cryptocurrency transaction. The method also includes transmitting the signed cryptocurrency transaction to a node of a blockchain network, and receiving a cryptocurrency transaction identifier from the node. The method also comprises generating a cryptogram using at least an access token on the mobile application and at least some of the transaction data.

A cryptocurrency system of the present disclosure employs one or more creator computing devices, one or more initial transaction computing devices, one or more asset-backed computing devices, one or more certifier computing devices, and one or more block chain verifier computing devices. In operation, the system enables a person or legal entity to create and manage electronic currency that is backed by assets.

Embodiments include methods and systems for linking high-value tokens using a low-value token, comprising receiving, from an electronic data server, a first high-value token and a request for a low-value token, the first high-value token being associated with sensitive data associated with a user, and the low-value token being associated with a subset of the sensitive data associated with the user. The methods and systems further comprise providing the low-value token to the electronic data server, and receiving, from a second electronic data server, the low-value token and a request for a second high-value token, the low-value token having been provided to the second electronic data server by the electronic data server. The methods and systems further comprise generating a second high-value token associated with the sensitive data associated with the user, and providing the second high-value token to the second electronic data server.