A server device stores data sent from a client device together with data identification information and stakeholder identification information that identifies a stakeholder operating the client device. A controller determines a number of stakeholders included in the data, and, in a case where the data stores information on stakeholders of a plurality of n organizations, leaves information on a specific stakeholder unrewritten and rewrites information of other stakeholders with optional information to generate n types of management data. The controller generates first hash value for each of the n types of management data, and controls n transactions including the first hash value to be issued to a blockchain, and transmits the transaction. The controller returns, in response to a browsing request specifying the data identification information and the stakeholder identification information from the client device, management data corresponding to the stakeholder identification information among the n types of management data.