摘要:
A content protection system prevents illegal key acquisition, without checking uniqueness of device keys. The content protection system includes a key data generation apparatus and a user terminal. The key data generation apparatus converts first key data, which is for using content, based on a predetermined conversion rule, thereby generating second key data, encrypts the second key data using a device key held by valid terminals, and outputs the encrypted key data. The user terminal obtains the encrypted key data, decrypts the encrypted key data using a device key held by the user terminal, thereby generating second key data, converts the second key data based on a re-conversion rule corresponding to the conversion rule, thereby generating the first key data, and uses the content with use of the generated first key data.
摘要:
A content protection system prevents illegal key acquisition, without checking uniqueness of device keys. The content protection system includes a key data generation apparatus and a user terminal. The key data generation apparatus converts first key data, which is for using content, based on a predetermined conversion rule, thereby generating second key data, encrypts the second key data using a device key held by valid terminals, and outputs the encrypted key data. The user terminal obtains the encrypted key data, decrypts the encrypted key data using a device key held by the user terminal, thereby generating second key data, converts the second key data based on a re-conversion rule corresponding to the conversion rule, thereby generating the first key data, and uses the content with use of the generated first key data.
摘要:
An authentication communication system is capable of storing information relating to revoked devices in less area than is conventionally required.A computer unit stores in advance revocation information that indicates at least one revoked apparatus, and when authenticating a driver unit judges, based on the revocation information, whether or not the driver unit is revoked. The computer unit prohibits communication with the driver unit when the driver unit is judged to be revoked, and communicates with the driver unit when the driver unit is judged not to be revoked.
摘要:
In an information input/output system, a user device inputs and outputs information to and from external sources including a key management device. The system includes the key management device that securely outputs invalid-device information specifying an invalid device unit that has been made invalid for use, and the user device that includes an input/output unit and a host unit. Via the input/output unit, input and output of information is enabled between the host unit and the external sources. The host unit securely receives, via the input/output unit, the invalid-device information outputted by the key management device and judges whether or not the input/output unit is an invalid device unit by referring to the received invalid-device information. When judging, that the input/output unit is an invalid device, the host unit thereafter prohibits input and output via the input/output unit. Due to this construction, the host unit can correctly judge whether or not the input/output unit is an invalid device unit.
摘要:
An encryption apparatus 100a is comprised of the following: a CRL storage unit 111 that stores a CRL; a device key ring storage unit 112 that stores a device key KD_A specific to each copyright protection module 210a used by a decryption apparatus 200a; a content key storage unit 113 that stores a content key Kc that is a secret key for encrypting a content; a hashing function processing unit 114 that calculates a hash value of the CRL stored in the CRL storage unit 111 according to a hashing function; an Ex-OR unit 115 that obtains an exclusive OR value between the hash value and the device key KD_A; and an Enc unit 116 that encrypts the content key Kc using an output value from the Ex-OR unit, and stores the hash value, the encrypted content key and the encrypted content in a DVD2a.
摘要:
An encryption apparatus 100a including: a CRL storage unit 111 storing a CRL; a device key ring storage unit 112 storing a device key KD_A specific to each copyright protection module 210a used by a decryption apparatus 200a; a content key storage unit 113 storing a content key Kc that is a secret key for encrypting a content; a hashing function processing unit 114 calculating a hash value of the CRL stored in the CRL storage unit 111 according to a hashing function; and an Ex-OR unit 115 obtaining an exclusive OR value between the hash value and the device key KD_A. The encryption apparatus also includes an Enc unit 116 encrypting the content key Kc using an output value from the Ex-OR unit, and storing the hash value, the encrypted content key and the encrypted content in a DVD2a.
摘要:
An authentication system is provided having a revocation list generation apparatus that constructs and stores a revocation list in a tree structure, the revocation list generation apparatus being used in combination with a revocation judgment apparatus. The authentication system improves upon conventional authentication systems because the memory capacity to store a Certificate Revocation List (CRL) in order to identify revoked certificates is reduced. The tree structure corresponds to public key certificate, which are identified by leaf identifies, and nodes from a leaf that corresponds to a revoked public key certificate.
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).
摘要:
An encryption device, a decrypting device, a secret key generation device, a copyright protection system and a cipher communication device including: a CRL memory unit memorizing a CRL, a device key ring memory unit memorizing a specific device key KD_A in every IC card used in a decrypting device, a content key memory unit memorizing a content key Kc, which is a secret key for decrypting content, and a hashing function processing unit calculating a hashing value of the CRL memorized in the CRL memory unit. The devices further including an Ex-OR unit carrying out an exclusive OR between the hashing value and the device key KD_A memorized in the device key ring memory unit, and an Enc unit encrypting the content key Kc memorized in the content key memory unit using an output value of an Ex-OR unit.
摘要:
An encryption device, a decrypting device, a secret key generation device, a copyright protection system and a cipher communication device including: a CRL memory unit memorizing a CRL, a device key ring memory unit memorizing a specific device key KD_A in every IC card used in a decrypting device, a content key memory unit memorizing a content key Kc, which is a secret key for decrypting content, and a hashing function processing unit calculating a hashing value of the CRL memorized in the CRL memory unit. The devices further including an Ex-OR unit carrying out an exclusive OR between the hashing value and the device key KD_A memorized in the device key ring memory unit, and an Enc unit encrypting the content key Kc memorized in the content key memory unit using an output value of an Ex-OR unit.