A storage device allows expanding user utilizable applications by storing
information permitted to be read according to a certificate and
information permitted to be read according to information determined by a
user. An information distributor receives a certificate from the storage
device and after verifying the certificate, transmits data of a license
and access control conditions to the storage device. After receiving data
of a certificate from an information browser, verifying the certificate
and imposing a limit on access based upon one of access control
conditions, the storage device transmits data of the license and the
other to the information browser. The information browser permits
utilization of the license under the limitation defined by the access
control condition. The certificate includes either or both of a
certificate approved by a certificate authority and a PIN (personal
identifying number) determined by the user.