INFORMATION PROCESSING APPARATUS AND INFORMATION PROCESSING METHOD PERFORMING DECODING OR ENCRYPTION

Abstract

An information processing apparatus is provided which processes stream data including, in a non-encrypted region, pointer information designating keys used for decoding of data in an encrypted region of the stream data. In this processing, the apparatus detects change of the pointer information extracted in decoding of the stream data, and generates a decoding key of the stream data on the basis of key generation data, in response to a trigger of agreement between the changed pointer information and information set separately. The method decodes the data in the encrypted region of the stream data by using the generated decoding key.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A general architecture that implements the various feature of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.

FIG. 1 is a diagram illustrating a configuration of a main part of a first information processing apparatus according to an embodiment.

FIG. 2 is a diagram illustrating an example of stream data to be processed by the configuration of FIG. 1.

FIG. 3 is a diagram illustrating an example of title key management data (key generation data) used in the configuration of FIG. 1.

FIG. 4 is a time chart illustrating an example of a flow of decoding (or encryption) executed by the configuration of FIG. 1.

FIG. 5 is a flowchart illustrating an example of decoding executed by the configuration of FIG. 1.

FIG. 6 is a flowchart illustrating an example of encryption executed by the configuration of FIG. 1.

FIG. 7 is a diagram illustrating an example of an information processing apparatus, in which the configuration of FIG. 1 is incorporated.

FIG. 8 is a diagram illustrating another example of the information processing apparatus, in which the configuration of FIG. 1 is incorporated.

FIG. 9 is a diagram illustrating another example of the information processing apparatus, in which the configuration of FIG. 1 is incorporated.

FIG. 10 is a diagram illustrating an example of an optical disc playback apparatus, in which the configuration of FIG. 1 is incorporated.

Claims

1. An information processing apparatus having a processing section, the processing section decoding a stream including non-encrypted pointer information and encrypted data to be decoded by key information designated by the pointer information, the information processing apparatus comprising: holding means for holding predetermined set information corresponding to the pointer information of the stream to be input; andstorage means for storing key generation data formed of a combination of the pointer information included in the stream and the key information designated by the pointer information,wherein the processing section includes:extracting means for extracting the pointer information included in the input stream;first detecting means for detecting change of the pointer information extracted by the extracting means;second detecting means for detecting that the pointer information, change of which has been detected by the first detecting means, agrees with or corresponds to the set information corresponding to the changed pointer information and held in the holding means;key generation means for obtaining key information corresponding to the pointer information included in the input stream from the key generation data stored in the storage means, and generating a decoding key, when the second detecting means detects agreement or correspondence between the pointer information and the set information; anddecoding means for detecting the encrypted data included in the stream by using the decoding key generated by the key generation means, and outputting the stream including the decoded data.

2. An information processing apparatus according to claim 1, wherein if the first detecting means detect change of the pointer information, the second detecting means does not detect the agreement or correspondence and there is the decoding key generated before the detection, the decoding means decodes the encrypted data by using the decoding key.

3. An information processing apparatus according to claim 1, wherein the processing section is provided with at least one of the holding means for holding the predetermined set information and the storage means for storing the key generation data.

4. An information processing apparatus according to claim 1, further comprising: a processor which controls operation of the processing section,wherein at least one of the holding means for holding the predetermined set information and the storage means for storing the key generation data is provided in the processor.

5. An information processing apparatus according to claim 1, further comprising a reading device which reads the pointer information and the encrypted data from an information storage medium storing the stream.

6. An information processing apparatus having a processing section, the processing section generating a stream including non-encrypted pointer information and data to be encrypted by key information designated by the pointer information, the information processing apparatus comprising: holding means for holding predetermined set information corresponding to the pointer information of the stream to be input; andstorage means for storing key generation data formed of a combination of the pointer information included in the stream and the key information designated by the pointer information,wherein the processing section includes:extracting means for extracting the pointer information included in the input stream;first detecting means for detecting change of the pointer information extracted by the extracting means;second detecting means for detecting that the pointer information, change of which has been detected by the first detecting means, agrees with or corresponds to the set information corresponding to the changed pointer information and held in the holding means;key generation means for obtaining key information corresponding to the pointer information included in the input stream from the key generation data stored in the storage means, and generating an encrypting key, when the second detecting means detects agreement or correspondence between the pointer information and the set information; andencrypting means for encrypting the data included in the stream by using the encrypting key generated by the key generation means, and outputting the stream including the encrypted data.

7. A method of decoding a stream including non-encrypted pointer information and encrypted data to be decoded by key information designated by the pointer information, comprising: storing key generation data formed of a combination of the pointer information included in the stream and the key information designated by the pointer information, and setting predetermined set information corresponding to the pointer information of the stream to be input;extracting the pointer information included in the input stream;detecting change of the extracted pointer information;detecting that the pointer information, change of which has been detected, agrees with or corresponds to the set information corresponding to the changed pointer information;obtaining key information corresponding to the pointer information included in the input stream from the key generation data, and generating a decoding key, when agreement or correspondence between the pointer information and the set information is detected; anddecoding the encrypted data included in the stream by using the generated decoding key, and outputting the stream including the decoded data.

8. A method according to claim 7, wherein if change of the pointer information is detected, the agreement or correspondence is not detected and there is the decoding key generated before the detection, the encrypted data is decoded by using the decoding key.

9. A method of generating a stream including non-encrypted pointer information and data to be encrypted by key information designated by the pointer information, comprising: preparing key generation data formed of a combination of the pointer information included in the stream and the key information designated by the pointer information, and setting predetermined set information corresponding to the pointer information of the stream to be input;extracting the pointer information included in the input stream;detecting change of the extracted pointer information;detecting that the pointer information, change of which has been detected, agrees with or corresponds to the set information corresponding to the changed pointer information;obtaining key information corresponding to the pointer information included in the input stream from the key generation data, and generating an encrypting key, when agreement or correspondence between the pointer information and the set information is detected; andencrypting the data included in the stream by using the generated encrypting key, and outputting the stream including the encrypted data.

10. A method according to claim 9, wherein if change of the pointer information is detected, the agreement or correspondence is not detected and there is the decoding key generated before the detection, the data is encrypted by using the encrypting key.