JP2004112038A5

JP2004112038A5 -

Info

Publication number: JP2004112038A5
Application number: JP2002268265A
Authority: JP
Filing date: 2002-09-13
Publication date: 2005-09-02
Anticipated expiration: 2022-09-13

Claims

A data management information encryption device for creating data management information for obtaining the media key by encryption on a recording medium on which digital data encrypted based on the media key is recorded and recording the data on the recording medium There,
Key generation means for generating a plurality of keys;
Based on a plurality of keys generated by the key generation means, multiple encryption means for encrypting the media key and recording the obtained data management information on the recording medium;
A data management information encryption apparatus comprising:

For recording media on which digital data encrypted based on the media key is recorded,
A data management information encryption device for creating first to third data management information for obtaining the media key by encryption and recording the information on the recording medium,
Key generation means for generating first to third keys and first to third key indexes;
A fixed key generation means for generating a fixed key;
First data management information recording means for encrypting the fixed key based on the first key and recording the obtained first data management information in the recording medium in association with the first key index;
Intermediate key generating means for generating an intermediate key;
The intermediate key is encrypted based on the second key, the obtained encrypted intermediate key is encrypted based on the fixed key and the second key index, and the obtained second data management information is stored in the second key. Second data management information recording means for recording on the recording medium in association with a key index;
The media key is encrypted based on the third key, the obtained encrypted media key is encrypted based on the intermediate key, and the obtained third data management information is associated with the third key index in the recording Third data management information recording means for recording on the medium;
A data management information encryption apparatus comprising:

With respect to a recording medium on which digital data encrypted based on a media key and data management information obtained by multiplexing the media key based on a plurality of keys are recorded.
A decryption device comprising a drive unit for reading recorded content from the recording medium, and a host unit for obtaining the media key based on the read content of the drive unit,
The drive unit is
Key storage means in which any one of the plurality of keys is stored;
Decrypting the data management information read from the recording medium based on the key in the key storage unit, and transmitting the decryption result to the host unit, and
The host unit is
Of the plurality of keys, remaining key storage means in which a key that is not in the key storage means of the drive unit is stored;
Intermediate key decryption means for decrypting the decryption result transmitted from the decryption means of the drive unit based on the key in the remaining key storage means, and obtaining an intermediate key;
The other media management information read from the recording medium through the drive unit is decrypted based on the intermediate key, the decryption result is decrypted based on the other key in the remaining key storage means, and the obtained media key Media key decryption means for outputting
A decoding device comprising:

Digital data encrypted based on the media key,
First data management information (information obtained by encrypting a fixed key based on the first key) for obtaining the media key;
Second data management information (information obtained by encrypting the intermediate key based on the second key and encrypting the obtained encrypted intermediate key based on the fixed key and the second key index);
For a recording medium on which third data management information (information obtained by encrypting the media key based on the third key and encrypting the obtained encrypted media key based on the intermediate key) is recorded ,
A drive unit for reading recorded content from the recording medium; and a host unit for obtaining the media key based on the read content of the drive unit, the first to third keys and the first to third keys A decryption device that holds a key index,
The drive unit is
First key storage means in which the first key and the first key index are stored in advance;
Fixed key decryption means for decrypting the first data management information read from the recording medium based on the first key in the first key storage means to obtain the fixed key;
Index decrypting means for decrypting the encrypted second key index transmitted from the host unit and obtaining the second key index;
Intermediate key first decryption means for decrypting second data management information read from the recording medium based on the fixed key and the second key index, and transmitting the obtained encrypted intermediate key to the host unit; , And
The host unit is
Second and third key storage means in which the second key and the second key index and the third key and the third key index are stored in advance;
Index encryption means for encrypting the second key index in the second third key storage means and transmitting the obtained encrypted second key index to the index decryption means;
Intermediate key second decryption means for decrypting the encrypted intermediate key transmitted from the intermediate key first decryption means based on the second key in the second third key storage means, and obtaining the intermediate key;
The third data management information read from the recording medium via the drive unit is decrypted based on the intermediate key, and the obtained encrypted media key is used as the third key in the second third key storage means. A media key decrypting means for decrypting based on the result and outputting the obtained media key;
A decoding device comprising:

Decrypt based on the data management information on a recording medium on which the digital data encrypted based on the media key and the data management information obtained by multiplexing the media key based on a plurality of keys are recorded. A decoding management method for managing decoding by a device, comprising:
Recording data management information of different values on the recording medium for each type of the decoding device;
Preparing key information for decrypting corresponding data management information for each decryption device;
When a decoding device to be excluded occurs, the sale of the recording medium is stopped, and a new recording medium in which the data management information corresponding to the decoding device is rewritten with another information,
A decryption management method comprising: