Remapped sectors: Data security

  • Thread starter Thread starter Ludwig
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Previously said:
people trust them , that's it.
Click to expand...

Hey, maybe I should start this type of business too!
No wait, I am to honest. Damn, another opportunity to get rich lost...

Arno
 
Hi,
first speaking about Blancco, first You should visit their website and
read about their software.
Read this:
http://www.blancco.com/main.site?action=3Dsiteupdate/view&id=3D13 and you
will see why people trust them.

Happy new Year!

M=8E
Click to expand...


There's a security paper that's a few years old, now that adresses
secure deletion. Some of the technology may have changed,
or may not.

This paragraph stated that it is possible, at least in some cases, but
not easily. There's no question in my mind that all the hard disk
manufacturers will assist legit government agencies in doing whatever
is possible.

http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

The handling of mapped-out sectors and tracks is an issue
which can't be easily resolved without the cooperation of hard
drive manufacturers. Although some SCSI and IDE hard drives
may allow access to defect lists and even to mapped-out areas,
this must be done in a highly manufacturer- and drive-specific
manner. For example the SCSI-2 READ DEFECT DATA command can be
used to obtain a list of all defective areas on the
drive. Since SCSI logical block numbers may be mapped to
arbitrary locations on the disk, the defect list is recorded
in terms of heads, tracks, and sectors. As all SCSI device
addressing is performed in terms of logical block numbers,
mapped-out sectors or tracks cannot be addressed. The only
reasonably portable possibility is to clear various automatic
correction flags in the read-write error recovery mode page to
force the SCSI device to report read/write errors to the user
instead of transparently remapping the defective areas. The
user can then use the READ LONG and WRITE LONG commands (which
allow access to sectors and extra data even in the presence of
read/write errors), to perform any necessary operations on the
defective areas, and then use the REASSIGN BLOCKS command to
reassign the defective sections. However this operation
requires an in-depth knowledge of the operation of the SCSI
device and extensive changes to disk drivers, and more or less
defeats the purpose of having an intelligent peripheral.
 
Previously said:
Hi,
first speaking about Blancco, first You should visit their website and
read about their software.
Read this:
http://www.blancco.com/main.site?action=siteupdate/view&id=13 and you
will see why people trust them.
Click to expand...

Well, I see nothing there that gives me any trust in the claim that
they can _reliably_ overwrite remapped sectors. It is just a big
collection of missleading statements. Sorry, but you fell for the
PR lies. (Lies by omission asr lies in my book as well, especially
in the field of security.)

Example:
DoD 5220.22-M is from the beginning of 1995.

For "clearing" of data on a "Non-Removable Rigid Disk" it says (get this):

"Overwrite all addressable locations with a single character."


For "sanitisation" it requires physical degaussing, physical
destruction or
"Overwrite all addressable locations with a character, its
complement, then a random character and verify.
THIS METHOD IS NOT APPROVED FOR SANITIZING MEDIA THAT CONTAINS
TOP SECRET INFORMATION."

The document never mentions and does not seem to be aware of relocated,
not directly addressable sectors. Also note that they wisely do not
allow anything besides physical destruction for top secret information.

The above info is from section 8-306 of DoD 5220.22-M which you can
find, e.g., here: http://www.dss.mil/isec/nispom_0195.htm
Happy new Year!
Click to expand...

Thanks! Same to you and all others here!

Arno
 
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