Re: [dm-crypt] Two questions

[Arno Wagner <arno@wagner.name>]

On Wed, Nov 13, 2019 at 19:42:55 CET, mgreger@cinci.rr.com wrote:
>    From Michael Kjörling:
> 
>    > Yes; it implies that the two volumes are encrypted using the same
>    master key (as well as being accessible using the same set of
>    passphrases), _and_ it makes it obvious that this is the case.
> 
>    (Assume any detached header is absent)
> 
>    Obvious by inspecting the raw encrypted drives? My concern is salt/iv
>    reuse for same sector #'s on multiple drives leading to information
>    leakage.
> 
>    For example let's say two encrypted drives were mirrored. Using the
>    same master key would make it obvious they are mirrored, but no
>    additional information is leaked (other than that they are in fact
>    copies of each other). But more complex scenarios exist: RAID, LVM2
>    headers, etc. Those other scenarios are the ones I am curious about.

You may also have sectors in filesystems that are generally the same 
and that would be obvious. 

The simple answer is: If you care, then do not do this. Otherwise
you do not care and it is not a problem. No amount of analysis will
make this go away.

Regards,
Arno

-- 
Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno@wagner.name
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
----
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