US Patent 11507929 Digital fiat currency

Techniques are disclosed which include receiving, by a central entity computer, a request for digital currency. The request includes a serial number and a denomination of a physical currency. The central entity computer generates the digital currency for the denomination and linked to the serial number. The generating includes recording the digital currency on a blockchain. The central entity computer transmits a notification of the generation of the digital currency. The central entity computer causes removal of the physical currency from circulation in a fiat currency system.