Patent ID: 7680280

Claim:
An electronic device, comprising: a mounting device which loads a portable recording medium; and an encrypted information write device which writes encrypted information obtained by encrypting predetermined information using an electronic device unique key unique to the electronic device, and an electronic device unique key encrypted using a recording medium unique key unique to the recording medium, in the recording medium; the electronic device further comprising: an authentication device which authenticates medium identification information for identifying the recording medium, and device identification information for identifying the electronic device, in the case where the recording medium is mounted on the mounting device; a key generating device which generates a common encryption key for encrypting or decrypting the electronic device unique key in accordance with the authentication result of the authentication device; an encrypted information read device which reads the encrypted information recorded in the recording medium, and the encrypted electronic device unique key; an acquiring device which forwards the read electronic device unique key to a control portion for the recording medium, and acquiring the electronic device unique key encrypted by the common encryption key from the control portion, after the electronic device unique key is decrypted by the recording medium unique key in the control portion; a decryption execution device which decrypts the acquired electronic device unique key by the common encryption key, and executing the decryption of the encrypted information using the decrypted electronic device unique key; and a control device which sets the electronic device in usable mode in the case where the encrypted information is decrypted by the decryption execution device.