[Discuss] TrueCrypt with SSD

[Richard Pieri]

On Aug 15, 2011, at 7:45 AM, Edward Ned Harvey wrote:
> 
> Incidentally, what *is* the problem with TrueCrypt anyway?  It seems to me,
> a hard drive looks like a hard drive whether it's a HDD or SSD.

That's the problem: SSDs *aren't* HDDs.  They don't work the same.  One of the specific issues is wear leveling.  What this means is that you write a block out to flash.  When you write the same block it gets written to a different set of flash cells so that wear is spread out more or less evenly across the flash chip.  Which means that there will be unencrypted data lying around inside there somewhere that the OS can't see but can be recovered via deep forensic analysis.

TRIM compounds this by intentionally freeing blocks for wear leveling, making SDDs potentially very vulnerable to known plaintext attacks.  In short, flash drives cannot be made reliably secure by external encryption mechanisms.  At best it is a best effort.

--Rich P.