US Patent 10366378 Processing transactions in offline mode

In some examples, methods and systems may process one or more payment transactions between a merchant and a buyer by detecting buyer's communication device as an instrument to approve or reject a payment transaction in offline mode. The method includes detecting at least one transaction activity associated with a payment system, establishing a communication channel between the POS terminal an RF communication device in proximity to the POS terminal to obtain at least one device characteristic of the communication device, related to the operational or physical features of the communication device; generating a digital fingerprint based in part on the obtained device characteristic and the information related to received payment object; determining whether the digital fingerprint substantially compares to an existing fingerprint in a database and if the existing fingerprint is substantially similar to the digital fingerprint, rejecting the payment transaction through presence of the communication device.