Patent ID: 11972119
Assignee: HITACHI, LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 3:
4. The storage system according to claim 2,
wherein the format management information stored in the memory includes information that associates an address range indicating a predetermined storage area provided in the storage device with the format of the cryptographic operation corresponding to the storage device,
wherein when the request by the host terminal is a request of reading the encrypted data from the storage area at the storage device address in the storage device, the processor is configured to generate the storage device instruction information that includes information on the request type indicating the request of reading, on the storage device address, and on a third memory address that is of the memory and is for designating the storage area that stores the encrypted data read from the storage device,
upon receipt of the storage device instruction information, the storage device is configured to read the encrypted data from the storage area at the storage device address, and stores the read encrypted data in the storage area at the third memory address,
the processor is configured to generate the circuit instruction information that includes information on the request type indicating the request for reading, on the identification information about the encryption key corresponding to the storage device address, on the third memory address, on a fourth memory address that is of the memory and is for designating the storage area that stores data obtained by decrypting the encrypted data, and on the format of the cryptographic operation corresponding to the storage device, and
upon receipt of the circuit instruction information, the cryptographic operation circuit is configured to:
read, from the memory, the encrypted data stored in the storage area at the third memory address;
read the encryption key associated with the identification information, from the stored key information; and
store the data obtained by decrypting the encrypted data using the encryption key according to the format, in the storage area at the fourth memory address, and

the processor is configured to reply to the host terminal with the data stored in the storage area at the fourth memory address.