An information processing device according to one embodiment of the present feature comprises a transmission unit and an execution unit. The transmission unit transmits, to a blockchain, encrypted contract information relating to a payer who pays a prescribed amount of money and a recipient who receives the prescribed amount of money. The execution unit automatically executes payment on the basis of the contract information. Thus, automatic payment is made possible while protecting the privacy of contract information managed by the blockchain. Additionally, various use cases can be flexibly handled, in a state in which privacy is protected, by using the functionalities of the blockchain and a smart contract.