Patent ID: 7539873

Claim:
A data storing method of storing digital information which has a value, the data storing method is used in a system including an issuer apparatus issuing the digital information and a user apparatus, the method comprising: adding, by the issuer apparatus, a signature of the issuer apparatus to the digital information; generating, by the issuer apparatus, a manifest corresponding to the digital information; generating, by the issuer apparatus, accreditation information with the signature, and sending the digital information with the signature and the accreditation information with the signature to the user apparatus, wherein the accreditation information includes information corresponding to verification keys that correspond to third parties that are trusted by the issuer apparatus and that assure tamper-proof capability of the user apparatus; storing, by the user apparatus, the digital information and the accreditation information in first storing means of the user apparatus; sending, by the issuer apparatus, information that includes the manifest with the signature to the user apparatus; and verifying, by the user apparatus, the manifest with the signature by using a verification function for verifying the signature, and storing the manifest in second storing means that is tamper-proof only when the manifest is verified.