US Patent 11893570 Token based demand and remand system

A system is described to authorize a transaction using blockchain technology. For example, a transaction authorization system comprises a point of sale (POS) device, a mobile device, and a payment blockchain. The POS device can initiate a transaction by scanning one or more items to be purchased and generating a code comprising a transaction identifier and a total cost of the one or more items. The mobile device can receive the code and can generate a token comprising the transaction identifier, total cost, a selected payment method identifier, and a value that can identify an account of a person associated with the mobile device. The token is sent to a payment blockchain to authorize the transaction.