Seagate ST91000640NS ユーザーズマニュアル

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Constellation.2 Serial ATA Product Manual, Rev. B
6.6
Cryptographic erase
A significant feature of SEDs is the ability to perform a cryptographic erase. This involves the host telling the 
drive to change the data encryption key for a particular band. Once changed, the data is no longer recoverable 
since it was written with one key and will be read using a different key. Since the drive overwrites the old key 
with the new one, and keeps no history of key changes, the user data can never be recovered. This is tanta-
mount to an instantaneous data erase and is very useful if the drive is to be scrapped or redispositioned. 
6.7
Authenticated firmware download
In addition to providing a locking mechanism to prevent unwanted firmware download attempts, the drive also 
only accepts download files which have been cryptographically signed by the appropriate Seagate Design 
Center.
Three conditions must be met before the drive will allow the download operation:
1.
The download must be an SED file. A standard (base) drive (non-SED) file will be rejected.
2.
The download file must be signed and authenticated.
3.
As with a non-SED drive, the download file must pass the acceptance criteria for the drive. For example it 
must be applicable to the correct drive model, and have compatible revision and customer status.
6.8
Power requirements
The standard drive models and the SED drive models have identical hardware, however the security and 
encryption portion of the drive controller ASIC is enabled and functional in the SED models. This represents a 
small additional drain on the 5V supply of about 30mA and a commensurate increase of about 150mW in 
power consumption. There is no additional drain on the 12V supply. See the tables in Section 3.8 for power 
requirements on the standard (non-SED) drive models.
6.9
Supported commands
The SED models support the following two commands in addition to the commands supported by the standard 
(non-SED) models as listed in Table 6:
• Security Protocol Out (B5h)
• Security Protocol In (A2h)
6.10
RevertSP
The SED models will support RevertSP feature where it erases all data in all bands on the device and returns 
the contents of all SPs (Security Providers) on the device to their Original Factory State.