摘要:
In an encrypted communication system that includes a first and a second device, the first device encrypts a 1st key using a public key of the second device to generate 1st encrypted data, which is then transmitted to the second device, receives 2nd encrypted data from the second device, which is then decrypted using a secret key of the first device to obtain a 2nd key, and generates, based on the 1st and 2nd keys, a 1st encryption key for use in communication with the second device. The second device encrypts a 3rd key using a public key of the first device to generate the 2nd encrypted data, which is then transmitted to the first device, receives the 1st encrypted data, which is then decrypted using a secret key of the second device to obtain a 4th key, and generates, based on the 3rd and 4th keys, a 2nd encryption key for use in communication with the first device. The first and second devices perform encrypted communication using the 1st and 2nd encryption keys.
摘要:
A transmission apparatus performs a one-way operation on plaintext to generate a first value and transmits the first value, generates first additional information, performs an invertible operation on the plaintext and first additional information to generate connected information, encrypts the connected information using an encryption algorithm to generate ciphertext, and transmits the ciphertext. A reception apparatus receives the first value and the ciphertext, generates second additional information identical to the first additional information, decrypts the ciphertext using a decryption algorithm, which is an inverse-conversion of the encryption algorithm, to generate decrypted connected information, decrypts the decrypted connected information and the second additional information according to an inverse of the invertible operation to generate decrypted text, performs the one-way operation on the decrypted text to generate a second value, compares the first and second values, and judges that the decrypted text is valid only when the first and second values match.
摘要:
The present invention pertains to a transmission apparatus for generating an encrypted text by encrypting a plaintext, which includes a parameter storage unit for storing a random parameter (the number of terms whose coefficients indicate 1) adapted to an encryption key and an encryption apparatus and a decryption apparatus; an encryption unit for generating, from the plaintext, the encrypted text using the encryption key and the random parameter stored in the parameter storage unit, complying with an encryption algorithm based on the NTRU™ method; and a key updating unit for updating the random parameter stored in the parameter storage unit and the encryption key, as time passes.
摘要:
A data processing device for playing back a digital work reduces the processing load involved in verification by using only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on a DVD. In addition, the data processing device improves the accuracy of detecting unauthorized contents by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
Processing load on an executing device for conducting playback is high during the playback of contents since the executing device performs verification of the contents validity in parallel with the contents playback, and therefore the executing device has to be equipped with a highly efficient processor. The present invention reduces the processing load involved in the verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units consisting encrypted contents recorded on the DVD. In addition, the present invention is capable of improving the accuracy of detecting unauthorized contents to some extent by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
Processing load on an executing device for conducting playback is high during the playback of contents since the executing device performs verification of the contents validity in parallel with the contents playback, and therefore the executing device has to be equipped with a highly efficient processor. The present invention reduces the processing load involved in the verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on the DVD. In addition, the present invention is capable of improving the accuracy of detecting unauthorized contents to some extent by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
A reception apparatus includes a first timer and sends to a distribution apparatus a first date-time clocked by the first timer. The distributing apparatus includes a second timer, and generates expiry information based on a difference obtained by subtracting, from the first date-time, a second date-time that is clocked by the second timer. The expiry information is used to adjust a usage expiry date-time of content. The reception apparatus judges whether playback of the content is permitted based on the first timer and the expiry information. With this arrangement, unauthorized use of the content beyond the expiry date-time is prevented.
摘要:
An executing device for conducting playback is high during the playback of contents. The executing device is equipped with a highly efficient processor and reduces the processing load involved in verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on a DVD. In addition, the executing device is capable of improving the accuracy of detecting unauthorized contents by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
Processing load on an executing device for conducting playback is high during the playback of contents since the executing device performs verification of the contents validity in parallel with the contents playback, and therefore the executing device has to be equipped with a highly efficient processor. The present invention reduces the processing load involved in the verification by using, for the verification, only a predetermined number of encrypted units selected randomly from multiple encrypted units consisting encrypted contents recorded on the DVD. In addition, the present invention is capable of improving the accuracy of detecting unauthorized contents to some extent by randomly selecting a predetermined number of encrypted units every time the verification is performed.
摘要:
A data processing device for playing back a digital work reduces the processing load involved in verification by using only a predetermined number of encrypted units selected randomly from multiple encrypted units constituting encrypted contents recorded on a DVD. In addition, the data processing device improves the accuracy of detecting unauthorized contents by randomly selecting a predetermined number of encrypted units every time the verification is performed.