Information processing apparatus, information processing method and program
First Claim
1. An information processing apparatus for carrying out a cryptographic process on information, comprising:
- a cryptographic processing unit; and
a recording medium having encrypted data stored thereon;
said cryptographic processing unit being operable to (i) generate a second encryption key different from a first encryption key by carrying out processing on the first encryption key according to a reverse sequence of at least a portion of a predetermined key generation sequence, the first encryption key being input from an external source and being provided for the encrypted data, (ii) generate a decryption key for decrypting the encrypted data by carrying out processing in accordance with the predetermined key generation sequence on the second encryption key, and (iii) decrypt the encrypted data stored on said recording medium using the decryption key.
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Accused Products
Abstract
When contents are copied or transferred from a first information processing apparatus to a second information processing apparatus, the contents are stored onto a recording medium of the second information processing apparatus as they are without decryption and re-encryption. The first information processing apparatus also supplies a title-unique key to the second information processing apparatus to be used by the second information processing apparatus for generating a title key which is also stored on the recording medium. In a content reproduction process carried out by the second information processing apparatus, a title-unique key is generated from its own keys, such as master, media and LSI keys, in accordance with a title-unique-key generation sequence based on the stored title key, and is used for decrypting the contents. As a result, it is possible to provide a processing configuration for efficiently performing an operation to copy contents from one information processing apparatus to another and an operation to store distributed contents onto a recording medium of a recipient apparatus.
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Citations
15 Claims
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1. An information processing apparatus for carrying out a cryptographic process on information, comprising:
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a cryptographic processing unit; and
a recording medium having encrypted data stored thereon;
said cryptographic processing unit being operable to (i) generate a second encryption key different from a first encryption key by carrying out processing on the first encryption key according to a reverse sequence of at least a portion of a predetermined key generation sequence, the first encryption key being input from an external source and being provided for the encrypted data, (ii) generate a decryption key for decrypting the encrypted data by carrying out processing in accordance with the predetermined key generation sequence on the second encryption key, and (iii) decrypt the encrypted data stored on said recording medium using the decryption key. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of performing a cryptographic process on information in an information processing apparatus, the method comprising:
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providing a recording medium having encrypted data stored thereon;
generating a second encryption key different from a first encryption key by carrying out processing on the first encryption key according to a reverse sequence of at least a portion of a predetermined key generation sequence, the first encryption key being input from an external source and being provided for the encrypted data;
generating a decryption key for decrypting the encrypted data by carrying out processing in accordance with the predetermined key generation sequence on the second encryption key; and
decrypting the encrypted data stored on the recording medium using the decryption key. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A computer-readable medium recorded with a program to be executed in a computer system for carrying out a cryptographic process on information, the program comprising:
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generating a second encryption key different from a first encryption key by carrying out processing on the first encryption key according to a reverse sequence of at least a portion of a predetermined key generation sequence, the first encryption key being input from an external source and being provided for encrypted data;
generating a decryption key for decrypting the encrypted data by carrying out processing in accordance with the predetermined key generation sequence on the second encryption key; and
decrypting the encrypted data using the decryption key.
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Specification