Some recent SED SSDs/HDDs support scrambling the cryptographic key when SECURITY ERASE UNIT (F4h) is invoked (via normal or enhanced, sometimes both). This can be in addition to, or instead of, overwriting/erasing the user data area. However, it's never really clear if this is occurring, as the function is usually a vendor-specific addition to the requirements: some vendors explain that they do this in their specifications, others do not.
[New ATA function called SANITIZE]
There's a newish T13-published function called SANITIZE (B4h), which includes one or more of three possible sub-functions: BLOCK ERASE EXT (0012h), CRYPTO SCRAMBLE EXT (0011h) and OVERWRITE EXT (0014h).
CRYPTO SCRAMBLE EXT explicitly wipes the drive's data key(s) and creates new ones. If you rely on needing to re-key drives for security purposes, this is the function you want to depend on.
IDENTIFY DEVICE has additional flags available to indicate support for SANITIZE and which sub-functions are available.
[Where it exists]
The only software I have run across of that actually implements this is the drive erase function in contemporary Thinkpad BIOSes: the newest ones require a boot CD/floppy + BIOS support for safety reasons, older ones can be done directly through the BIOS alone once permanently activated via a utility CD. The most recent version is here: http://support.lenovo.com/en_US/downloads/detail.page?DocID=DS019026
There may be commercial software out there that also supports this new function.
The only hardware I've come across (in my limited experience) that supports this is the Crucial M500 series. I verified using above lenovo routine, which showed a complete bit-randomization pattern after the cryptographic scramble was invoked (verified via WinHex). I also notified Micron that their specification sheet indicated that the drive only supported OVERWRITE EXT, they agreed that was an error in their specifications which they are updating as it supports CRYPTO SCRAMBLE EXT instead.
PS - I forgot to mention a significant benefit: the routine returns in seconds, not minutes/hours.
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