A seller of blockchain-based media of value for fiat currency is matched to a buyer of the blockchain-based media of value. Terms or conditions of a transaction are agreed to between the parties. A transaction identifier for the transaction is created and blockchain-based media of value of the seller is obtained from the seller's wallet. Instructions for a smart contract are created; the smart contract controls release of the blockchain-based media of value based on its terms. The buyer visits a Self-Service Terminal (SST) deposits fiat currency in an amount dictated by the terms and the SST verifies the deposit and notifies the smart contract. The instructions of the smart contract cause the crypto currency to be transferred to the seller's wallet. The deposited fiat currency can be withdrawn at an SST by the seller or credited automatically to a financial account associated with the seller.