Data transfer control device, electronic instrument, and data transfer control method
First Claim
1. A data transfer control device for data transfer through a bus, comprising:
- a second memory access control circuit which encrypts data transferred from a first bus side in accordance with a second encryption process, and writes the thus-encrypted data to a second memory;
a third memory access control circuit which reads the encrypted data that has been written to the second memory, and transfers the thus-read encrypted data to a second bus side where a storage medium is connected; and
a first memory access control circuit which decrypts data by a first decryption process and writes the decrypted data to a first memory provided within the data transfer control device, the data having been encrypted by a first encryption process, which differs from the second encryption process, and then transferred from the first bus side,wherein the second memory access control circuit reads the data that has been written to the first memory, encrypts the thus-read data by the second encryption process, and writes the encrypted data to the second memory.
1 Assignment
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Accused Products
Abstract
Data to be transferred from a BUS1 (IEEE 1394 or USB) is encrypted by a second encryption process (DES) and the encrypted data is written to an external SDRAM through an external terminal of a data transfer control device. The encrypted data that has been written to the SDRAM is read through the external terminal, and the thus-read encrypted data is transferred to a BUS2 to which an HDD is connected. Encrypted data transferred from the BUS1 is decrypted by a first decryption process (DTCP), and is written to a small-capacity SRAM within the data transfer control device. The thus-written decrypted data is read from the SRAM and encrypted by the second encryption process. Paths that bypass the second encryption (or decryption) are also provided.
136 Citations
20 Claims
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1. A data transfer control device for data transfer through a bus, comprising:
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a second memory access control circuit which encrypts data transferred from a first bus side in accordance with a second encryption process, and writes the thus-encrypted data to a second memory; a third memory access control circuit which reads the encrypted data that has been written to the second memory, and transfers the thus-read encrypted data to a second bus side where a storage medium is connected; and a first memory access control circuit which decrypts data by a first decryption process and writes the decrypted data to a first memory provided within the data transfer control device, the data having been encrypted by a first encryption process, which differs from the second encryption process, and then transferred from the first bus side, wherein the second memory access control circuit reads the data that has been written to the first memory, encrypts the thus-read data by the second encryption process, and writes the encrypted data to the second memory. - View Dependent Claims (2, 3, 4, 5, 11, 12, 15, 16)
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6. A data transfer control device for data transfer through a bus, comprising:
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a third memory access control circuit which writes data to a second memory, the data having been encrypted by a second encryption process and transferred from a second bus side to which is connected a storage medium; a second memory access control circuit which reads the encrypted data that has been written to the second memory, decrypts the thus-read data by a second decryption process, and transfers the decrypted data to a first bus side; a first memory access control circuit, wherein; the second memory access control circuit reads encrypted data that has been written to the second memory, decrypts the thus-read data by the second decryption process, and writes the decrypted data to a first memory; the first memory access control circuit reads data that has been written to the first memory, encrypts the thus-read data by a first encryption process which differs from the second encryption process, and transfers the encrypted data to the first bus side. - View Dependent Claims (7, 8, 9, 10, 13, 14, 17, 18)
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19. A data transfer control method for data transfer through a bus, comprising:
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encrypting data transferred from a first bus side, by a second encryption process, and writing the encrypted data to a second memory provided outside a data transfer control device, through an external terminal of the data transfer control device; reading the encrypted data that has been written to the second memory, through the external terminal of the data transfer control device, and transferring the thus-read data to a second bus side to which is connected a storage medium; using a first memory access control circuit to decrypt data by a first decryption process and to write the decrypted data to a first memory provided within the data transfer control device, the data having been encrypted by a first encryption process, which differs from the second encryption process, and then transferred from the first bus side; and using the second memory access control circuit to read the data that has been written to the first memory, to encrypt the thus-read data by the second encryption process, and to write the encrypted data to the second memory.
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20. A data transfer control method for data transfer through a bus, comprising:
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writing data to a second memory provided outside a data transfer control device, through an external terminal of the data transfer control device, the data having been encrypted by a second encryption process and transferred from a second bus side to which is connected a storage medium; reading the encrypted data that has been written to the second memory, through the external terminal of the data transfer control device, decrypting the thus-read data by a second decryption process, and transferring the decrypted data to a first bus side; using the second memory access control circuit to read encrypted data that has been written to the second memory, to decrypt the thus-read data by the second decryption process, and to write the decrypted data to a first memory; and using a first memory access control circuit to read data that has been written to the first memory, to encrypt the thus-read data by a first encryption process which differs from the second encryption process, and to transfer the encrypted data to the first bus side.
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Specification