Patent ID: 7080259

Claim:
An IC card comprising: electronic wallet unit for management of electronic value information; electronic wallet storage unit that is the intrinsic storage area of the electronic wallet unit; electronic information registration unit registering said electronic value information to an electronic safe unit connected through a network and acquiring a registration certificate from the electronic safe unit; electronic information recovery unit for acquiring said electronic value information by presenting said registration certificate to said electronic safe unit; electronic information dividing unit for dividing said electronic value information to the desired number of partial electronic information pieces to which an identifier for recovering said electronic value information to the original electronic value information is respectively added; and an electronic information combining unit for recovering said electronic value information from said divided electronic information pieces, a key storage unit for storing a set of an encryption key for encrypting said electronic value information and a decoding key for decoding the encrypted electronic value information; and an encrypting/decoding unit for executing the encryption of said electronic value information using the encryption key and also executing the decoding using said decoding key, wherein said electronic registration unit acquires a plurality of partial electronic information pieces by requesting division of said electronic value information to said electronic information dividing unit and also acquires respective partial information registration certificates by registering the entire part or a part of said partial electronic information to the electronic safe unit, said electronic information recovery unit acquires respective corresponding partial electronic information pieces by presenting the entire part or a part of said partial information registration certificates to the electronic safe unit that has issued the respective partial information registration certificates, and said electronic information combining unit recovers said electronic value information from said obtained partial electronic information pieces.