In a blockchain, contents of a transaction are basically made public, and a malicious person can find system vulnerability of the blockchain. The person is likely to exploit the vulnerability and cause leak of cryptocurrency to an unintended third party through unauthorized access or the like. Thus, it cannot be said that sufficient security measures are taken. In the present invention, a colony server stores partial data containing data of a predetermined size from a beginning of valuables data received from a terminal, and a center server stores body data containing data of the predetermined size +1 and thereafter. Thus, the valuables data is managed in a divided manner. Also, even if the body data is leaked from the colony server through unauthorized access or the like, the body data is merely part of the valuables data, and has no value on its own. Thus, the present invention provides a system and the like for achieving robust security against unauthorized access.