Object to be solved is to achieve novel information management.
In order to solve the above circumstances, the present invention provides an information management system including: a blockchain stored in first and second nodes, in which the first or second node includes an authenticating means that executes an authentication process on a basis of feature data, the first node includes a first signing means that generates a first transaction signature and adds the first transaction signature to an unfinalized block in the blockchain, the second node includes a second signing means that generates a second transaction signature and adds the second transaction signature to the unfinalized block on a basis of a result of the authentication process and the first transaction signature, and the first node includes a chain updating means that hashes the unfinalized block and generates a block on a basis of the second transaction signature. According to the present invention, management of transaction on a network can be secured on the basis of individual authentication.