Processing method and apparatus for encrypted data transfer

A data processing method for encrypting/decrypting digital data for transfer from a storage device to a data processing apparatus comprising the steps of:

• transmitting encrypted digital data along with a storage encrypted content key from said storage device to said data processing apparatus;
• extracting said storage encrypted content key from said encrypted digital data in said data processing apparatus using a session key;
• transmitting said storage encrypted content key from said data processing apparatus to said storage device;
• storage decrypting said storage encrypted content key into a content key in said storage device using a storage use key;
• session encrypting said content key into a session encrypted content key in said storage device by said session key;
• transmitting said session encrypted content key from said storage device to said data processing apparatus;
• session decrypting said session encrypted content key back into said content key in said data processing apparatus by said session key;
• data decrypting said encrypted digital data in said data processing apparatus by said content key;
• and
• expanding and outputting the decrypted digital data to a speaker.

A data processing method for inputting and outputting digital data between a data processing apparatus and a storage device comprising the steps of:

• encrypting a content key by a session key;
• transmitting the content key encrypted by said session key from said data processing apparatus to said storage device;
• decrypting the content key from said data processing apparatus by said session key;
• encrypting the decrypted content key by a storage use key of said storage device;
• transmitting the content key encrypted by said storage use key from said storage device to said data processing apparatus;
• encrypting said digital data based on the content key from said storage device;
• transmitting the encrypted digital data along with the content key encrypted by said storage use key from said data processing apparatus to said storage device;
• and
• storing the encrypted digital data and the content key from said data processing apparatus.

A data processing apparatus for encrypting digital data, comprising:

• encryption means for encrypting a content key by a session key;
• interface means for outputting said content key encrypted by said session key to a storage device and for inputting the content key encrypted by a storage use key of said storage device;
• said encryption means encrypts said digital data based on the content key encrypted by said storage use key;
• and
• said interface means outputting the encrypted digital data along with the content key encrypted by said storage use key to said storage device.

A data storage device for storing encrypted digital data comprising:

• decryption means for decrypting a content key by a session key;
• encryption means for encrypting the decrypted content key by a storage use key;
• interface means for inputting the content key encrypted by said session key from a data processing apparatus, for outputting the content key encrypted by said storage use key, and for inputting the encrypted digital data along with the content key encrypted by said storage use from said data processing apparatus;
• and
• memory means for storing the encrypted digital data and the content key input from said data processing apparatus.

A data processing system for inputting and outputting digital data between a data processing apparatus and a storage device wherein;

• said data processing apparatus comprises:
• first encryption means for encrypting a content key by a session key,
• first interface means for outputting said content key encrypted by said session key to a storage device and for inputting the content key encrypted by a storage use key of said storage device,
• said first encryption means encrypts said digital data being based on the content key encrypted by said storage use key, and
• said interface means outputting the encrypted digital data along with the content key encrypted by said storage use key to said storage device;
• and
• said storage device comprises:
• decryption means for decrypting a content key from said data processing apparatus by said session key,
• second encryption means for encrypting the decrypted content key by said storage use key,
• second interface means for inputting the content key encrypted by said session key from a data processing apparatus, for outputting the content key encrypted by said storage use key and for inputting the encrypted digital data along with the content key encrypted by said storage use from said data processing apparatus, and
• memory means for storing the encrypted digital data and the content key input from said data processing apparatus.