Various embodiments are generally directed to continuous authentication of a user to a digital service based on activity of a contactless card positioned proximate to a computing device on which the digital service operates. For example, a series of periodic status messages may be provided between a client device and the contactless card to verify whether the contactless card remains active, wherein authorization to access the digital service continues while the contactless card is active, and terminates when the contactless card is inactive.

Provided are a method and system for payment when a network is blocked. A method of providing a remittance service performed by a first device, the method including requesting a financial institution system to issue a block key layer for at least a portion of an amount of money retained by a user of the first device, receiving the block key layer from the financial institution system in response to the request, receiving, from a second device, remittance request data for an amount of remittance, obtaining, from the received block key layer, a block key layer corresponding to the amount of remittance, and transmitting, to the second device, a file for the block key layer corresponding to the amount of remittance.

Example embodiments of systems and methods for data transmission system between transmitting and receiving devices are provided. In an embodiment, each of the transmitting and receiving devices can contain a master key. The transmitting device can generate a diversified key using the master key, protect a counter value and encrypt data prior to transmitting to the receiving device, which can generate the diversified key based on the master key and can decrypt the data and validate the protected counter value using the diversified key.

Example embodiments of systems and methods for data transmission system between transmitting and receiving devices are provided. In an embodiment, each of the transmitting and receiving devices can contain a master key. The transmitting device can generate a diversified key using the master key, protect a counter value and encrypt data prior to transmitting to the receiving device, which can generate the diversified key based on the master key and can decrypt the data and validate the protected counter value using the diversified key.

Methods are described for performing a timely authorization of digital credential data delivered from a mobile device that is without access to a local persistently stored permanent cryptographic key. An application executable in the operating system of a mobile device receives a first non-permanent cryptographic key associated with the account from a remote computer system, stores the first non-permanent cryptographic key as a local cryptographic key associated with the account; generates a response cryptogram using the local cryptographic key and without accessing the permanent cryptographic key and sends a device response communication from the mobile device to an electronic reader of a POS terminal, the device response communication comprising an application data protocol unit containing the response cryptogram and an account identifier for the account.

A method of determining a proximity of an antenna located in a payment instrument to an antenna located within an electronic device may include receiving, at the antenna located within the electronic device, a first signal from the antenna located in the payment instrument, the first signal received at a first time, receiving, at the antenna located within an electronic device, a second signal from the antenna located in the payment instrument, the second signal received at a second time, the second time being later than the first time, determining a difference in a signal strength between the first and second signals, and displaying, on a display of the electronic device, an indication based on the determination.

Systems and methods for processing transactions using a digital payment platform.

A processor of a computing device may receive, from a contactless card, a uniform resource locator (URL) and a cryptogram. An operating system (OS) executing on the processor may open an application based on the URL. The application may transmit the cryptogram to an authentication server. The application may receive, based on the server verifying the cryptogram, an account number. The application may store the account number in a memory of the device.

An electronic transaction verification system comprising a client subsystem, a merchant subsystem, and a transaction verification subsystem. The transaction verification subsystem receives a quantum payment serial number from the client subsystem and performs entangled quantum encryption on the received quantum payment serial number to generate an entangled quantum payment serial number. The verification subsystem encrypts the entangled quantum payment serial number and transmits the encrypted entangled quantum payment serial number to the merchant subsystem. The transaction verification subsystem also transmits the entangled quantum payment serial number to the client subsystem.

The present disclosure generally relates to a novel computer implemented method for performing an offline transaction between a first user operating a first electronic device and a second user operating a second electronic device. The present disclosure also relates to a corresponding first electronic device and a computer program product.