On October 3, at the b.tokyo of the Japan Blockchain Conference held by N.avenue Co., Ltd. in Tokyo, MIT's Michael Casey pointed out in the keynote speech "How the Blockchain Changes Society": Blockchain Technology as the Center Data management provides a solution. Facebook allows advertisers to settle in, through paid services, and centralized data management can generate data manipulation issues such as the 2016 US election. The amount of data processed globally is increasing, and if it is managed in a centralized organization? It is getting more and more difficult. The data is controlled by a large centralization organization, and ordinary people cannot compete with it, and the decentralized nature of the blockchain may help us.