On Thu, May 04, 2006 at 01:44:48PM -0500, Travis H. wrote:

> I guess perhaps the reason they don't do integrity checking is that it
> involves redundant data, so the encrypted volume would be smaller, or
> the block offsets don't line up, and perhaps that's trickier to handle
> than a 1:1 correspondence.

Exactly, many file systems rely on block devices with atomic single block
(sector) writes. If sector updates are not atomic, the file system needs
to be substantially more complex (unavoidable transaction logs to support
roll-back and roll-forward). Encrypted block device implementations that
are file system agnostic, cannot violate block update atomicity and so
MUST not offer integrity.


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