Secret information management scheme based on secret sharing scheme

摘要

In a secret information management system for managing a secret information of a user, the secret information is divided into a plurality of divided data by using a secret sharing scheme, such that the secret information can be recovered from a prescribed number of the divided data, and a part of the plurality of divided data is stored into a terminal of the user as user's divided data while a rest of the plurality of divided data are stored into one or more of deposit servers. Then, a plurality of re-divided data different from the plurality of divided data are generated, from a combination of the prescribed number of the divided data among the divided data stored in the deposit servers by using the secret sharing scheme, and a part of the plurality of re-divided data is stored into the terminal as newly generated user's divided data while a rest of the plurality of re-divided data are stored into the deposit servers as newly generated divided data.