Re: OT - Wipers

["Bryan J. Smith" <b.j.smith@ieee.org>]

Robert Citek <rwcitek@alum.calberkeley.org> wrote:
> CAUTION:  Note  that  shred relies on a very
> important assumption: that the filesystem overwrites
> data in place.  This is the traditional way to do things,
> but many modern filesystem designs do not satisfy this
> assumption.

It is a major problem inode filesystem designs in general. 
They use separate data and inode blocks.  This is especially
the case for advanced inode filesystems that do not
pre-allocate inodes, but allocate them dynamically.  But in
the end, a good erase program _should_ be able to trace the
full inode/links tree and wipe out everything.  That means
writing to absolute sector blocks for both the inodes and
data blocks.

Far too many designs are geared towards file allocation table
(FAT) designs like FAT, HPFS and NTFS, which have
pre-allocated blocks with absolute references.  But then
again, if the mere reference of the name of a file is
considered classified, then FAT designs can be _worse_ than
inode designs.  At least inodes reference files by numbers,
whereas FAT designs reference by names in other files
(directories).

> Real government standards are to melt the disk down to a
> slag.

Huh?  Depends on the classification.
Some only require degausing.


-- 
Bryan J. Smith                | Sent from Yahoo Mail
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