| 摘要 |
A storage system encrypts plain text from an external device and stores the cryptogram into a disk unit, decrypts stored data in the disk unit and transmits decrypted text to the external device. The plain and decrypted text must be in agreement when seen from the external device. If a failure occurs in the encrypting or decrypting process, the plain and decrypted text disagree. The storage system includes an encryption unit for encrypting first data, a decryption unit for decrypting the encrypted data into second data, and a comparison unit for comparing the first and second data. When the first and second data do not agree, the first data is encrypted by a different encryption unit and the encrypted data is decrypted into third data, whereupon the first and third data are compared. When the first and third data do not agree, a failure report is sent. |
