A method of payment terminal operation, including: receiving a payment collection request for a payment from an application, generating a payment initiation request for the payment, sending the payment initiation request to a secure processing system, switching the secure processing system from operation in an unsecured mode to operation in a secured mode in response to receipt of the payment initiation request, facilitating payment information entry, and receiving a payment response notification, generated based on the payment information, at the main processor.

Proposed is a blockchain-based virtual currency intermediation and distribution system according to a point return, which can calculate, at a set rate, the amount of return for points that are given or paid offline or online for a user's product purchase or service use, and either convert the calculated amount of point return into a cash currency stepwisely, or convert the calculated amount of point return into a virtual currency recordable on a blockchain according to accumulated points, thereby securing stability and complementarity to support virtual currency transactions.

The present invention relates to a lightweight data storage apparatus for graphic blockchains, at least comprising a common transaction construction module for a user to initiate new transactions and a network broadcast module for broadcasting the transactions, wherein the apparatus further comprises a combined-transaction constructing module and a transaction deleting module, wherein the combined-transaction constructing module serves to determine whether number of transactions initiated by an account satisfies a first predetermined condition, and if yes, execute a first lightening procedure on the transactions, and the transaction deleting module serves to execute a second lightening procedure on the transactions that have been processed by the first lightening procedure and now have validation references satisfying a second predetermined condition, after which the network broadcast module broadcasts the transactions obtained after the second lightening procedure. With the disclosed transaction-combining and reference-transaction-deleting scheme, data storage overheads of a graphic blockchain can be reduced.

The present disclosure provides a method for users to convert physical currency into digital currency and to store and transfer that digital currency from an electronic wallet by interfacing with one or more liquidity providers in a network of liquidity providers. The method and related systems can be accessed and implemented via dedicated application software on a user device, and do not require a bank account. A minimum reserve amount held by each liquidity provider ensures that conversions between digital and physical currency is always seamless, and transaction fees may be calculated at a fixed percentage of transacted funds.

The present disclosure discloses a method, device and node apparatus for blockchain permission control. The method comprises: receiving target information sent by a node apparatus; acquiring an account address of a configured account of the node apparatus; acquiring, according to the account address, from a predetermined block stored with the account address and an account permission corresponding to the account address, the account permission corresponding to the account address; and processing the target information according to the account permission accordingly. In the present disclosure, node apparatuses are configured with corresponding accounts, and performing permission control on the accounts can restrict permissions of different node apparatuses so as to ensure security and privacy of blockchain data.

Embodiments of a smart card and systems and methods for secure data access using a smart card are described. The smart card may be formed a substrate and may include a microprocessor, a memory containing an applet, a counter, and a unique identifier. The smart card may dynamically generate a unique uniform resource location (URL) and transmit the URL to via a contactless communication interface to securely facilitate data access from other devices.

A computer-implemented method for determining a vulnerability in a new exchange function for use in a cryptocurrency system. An attack amount of crypto tokens of the first type and a first attack amount of crypto tokens of the second type may be obtained, wherein the attack amount of crypto tokens of the first type can be obtained according to a first creation exchange function in exchange for the first attack amount of crypto tokens of the second type. A second attack amount of crypto tokens of the second type is obtainable in exchange for the attack amount of crypto tokens of the first type. If the second attack amount of crypto tokens of the second type exceed the first attack amount of crypto tokens of the second type by more than a threshold, a vulnerability is found.

A method for electronic transaction monitoring and reporting includes: determining whether the received transaction request is encrypted, upon determining that the received transaction request is not encrypted, sending a failure alert to the merchant, determining a receiving acquirer processor for the transaction request, and transmitting the transaction request to the determined acquirer processor.

A method for processing a payment transaction via a proxy guarantor includes: receiving a transaction request between a user and a merchant including payment device data associated with a payment device of the user of a payment type not accepted by the merchant, and an indicator causing the payment transaction to be processed as a proxy guarantor transaction; identifying a guarantor associated with the user having a payment device of a payment type accepted by the merchant; communicating an authorization request to an issuer system associated with the guarantor to cause the issuer system of the guarantor to authorize the payment transaction; receiving an authorization response from the issuer system of the guarantor, the authorization response including a payment transaction approval indicator; and communicating a settlement request to an issuer system of the user.

A system and method for card control includes a card control computing system configured to enforce a card control rule based upon transactions made with a payment card. The card control computing system includes a memory unit configured to store information associated with a card control dashboard, and a processing unit configured to cause presentation of the card control dashboard via a display associated with a remote computing device, such that the card control dashboard is associated with the payment card and the card control rule. The card control dashboard includes a user interface. The processing unit is further configured to receive an input via the user interface to activate or deactivate one or more features associated with the card control rule, and trigger the card control rule based upon the one or more features that are activated or deactivated.