摘要:
A cryptographic apparatus reads, from a portable storage medium, content data and cryptographic information specifying a certain part of the content data on which cryptographic processing is to be performed, specifies the certain part in the read content data based on the read cryptographic information, and performs one of encryption and decryption on the certain part. When, for example, the content data is formed from alternating headers and variable-length data sections, the cryptographic information is a program formed from an instruction sequence. The instruction sequence has the cryptographic apparatus detect a header in the content data, read the length of the variable-length data, and perform cryptographic processing on a part of the content data between a start point and an end point, the start point being a position relative to the header position, and the end point being a value resulting from adding the length to the start point.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.
摘要:
A key distribution system distributes key data for using content to a second encryption device that has been legitimately outsourced processing by a first encryption device. The first encryption device acquires permission information indicating that the first encryption device has permission to use the content, generates certification information by making an irreversible alteration the to permission information, and transmits the permission information and the certification information to the second encryption device. The second encryption device receives the permission information and the certification information, sends them to a key distribution device, and acquires the key data from the key distribution device. The key distribution device receives the permission information and the certification information, judges whether or not the certification information was generated by the by the first encryption device, and if judging in the affirmative, transmits the key data to the second encryption device.
摘要:
A semiconductor memory card comprising a control IC 302, a flash memory 303, and a ROM 304. The ROM 304 holds information such as a medium ID 341 unique to the semiconductor memory card. The flash memory 303 includes an authentication memory 332 and a non-authentication memory 331. The authentication memory 332 can be accessed only by external devices which have been affirmatively authenticated. The non-authentication memory 331 can be accessed by external devices whether the external devices have been affirmatively authenticated or not. The control IC 302 includes control units 325 and 326, an authentication unit 321 and the like. The control units 325 and 326 control accesses to the authentication memory 332 and the non-authentication memory 331, respectively. The authentication unit 321 executes a mutual authentication with an external device.
摘要:
A content reproduction apparatus (1) which reproduces digital contents, and includes a device key storage unit (110) holding a device key (110a) specific to the content reproduction apparatus (1) in a manner that does not allow access from outside the content reproduction apparatus (1). The content reproduction apparatus (1), also includes a device ID storage unit (19) holding device key index information (19a) that is in a one-to-one association with a device key (110a), an instruction code receiving unit (14a) receiving an instruction code to output index information, a device key index information obtainment processing unit (10a) outputting, to outside, the device key index information (19a) stored in the device ID storage unit (19) based on the instruction, and a device key index information output processing unit (11a).