Patent ID: 8433929

Claim:
A data management device for managing data written into a restricted area on a readable and writable recording medium by executing application programs, the restricted area being protected against any access other than by application programs verified based on a plurality of digital certificates, and each of a plurality of directories within the restricted area being accessible by a different one of the application programs, each digital certificate including a chain of a plurality of certificate portions, one of the plurality of certificate portions being a root certificate portion verifying a subordinate certificate portion and another of the plurality of certificate portions being a leaf certificate portion being verified by a superordinate certificate portion, each certificate portion of the plurality of certificate portions having, as text information relating to an owner of a corresponding one of the digital certificates, subject name information described therein, a directory accessible by a given one of the application programs being an application directory into which data is written by executing the given application program and is subordinate to an organization directory that is specified by a digital certificate attached to the given application program and that in turn is subordinate to a root certificate directory also specified by the digital certificate attached to the given application program, the data management device comprising: a verifier device that verifies an authenticity of an application program by extracting a public key from a leaf certificate included in a certificate chain of a plurality of certificate portions included in a digital certificate attached to the application program, and verifying, with use of the public key, a signature value that is acquired directly from the application; a mapper that, if the application program is verified, associates a directory accessible by the application program out of the plurality of directories with text information that is included in the digital certificate used for the verification and that relates to an owner of the digital certificate, the association by the mapper associating the specified organization directory with the subject name information described in the leaf certificate, and the specified root certificate directory with the subject name information described in the root certificate; and a presenter that extracts root certificate directories and organization directories in which data is written, creates, for each extracted root certificate directory and each extracted organization directory, one entry including the extracted directory and text information associated with the extracted directory, and presents the created entries.