Electronic device, control method thereof, security program and others

A method of controlling 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 method comprising the processes of:
• authenticating 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;
• generating a common encryption key for encrypting or decrypting the electronic device unique key in accordance with the authentication result;
• reading the encrypted information recorded in the recording medium, and the encrypted electronic device unique key;
• forwarding 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;
• decrypting 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
• setting the electronic device in usable mode in the case where the encrypted information is decrypted.

A computer-readable recording medium in which a security program is recorded, said security program being characterized in that a computer included in 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;
• is caused to function as:
• authenticating 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;
• generating a common encryption key for encrypting or decrypting the electronic device unique key in accordance with the authentication result;
• reading the encrypted information recorded in the recording medium, and the encrypted electronic device unique key;
• forwarding 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;
• decrypting 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
• setting the electronic device in usable mode in the case where the encrypted information is decrypted.