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recovering&reconstructing data from severely broken cd?

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PaulSanderson
(@paulsanderson)
Senior Member

Hugh the first quote I made was re a smoking gun - its not.

In your scenario I still doubt it would get to court - sweaty kit and a fragment of a book (that could arguably have been in a page from an online newspaper) - even more difficult to use if you can't put it in context amnd cant attribute something from the CD to the perp.

We are going around in circles here - there to my knowledge has never been any use made of anything like this - spare secrtors (from glists plists etc.) would be much easier to get and to my knowledge have never been used.

If the pros had better evidence they would use it (keep it simple), if they had to resort to a sector as in your scenario I very much doubt the CPS would bother.

Anyway old CD's were made from cabbage extract and degraded as soon as they were scratched )

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Posted : 16/10/2012 1:08 am
mscotgrove
(@mscotgrove)
Senior Member

I think hmorgan's summary is good.

The major problem is actually getting a sector. Sticking a CD together I have found impossible because the recording film is normally very damaged. Cut into multiple pieces is even more impossible, if you are trying to use any kind of reader. Hence in my mind, I assume only a microscope stands any chance. Any bit misread will of course invalidate any hash searching, unless the ECC can fix it.

I am not sure what the original question is asking
Is it - can data be found
OR
Is it safe to cut CDs up and be happy that data will not be found.

I cut my CDs once and am happy that no one will read anything - but I also don't have anything on my CDs that I consider 'top secret'.

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Posted : 16/10/2012 1:17 am
jaclaz
(@jaclaz)
Community Legend

I cut my CDs once and am happy that no one will read anything - but I also don't have anything on my CDs that I consider 'top secret'.

BUT, do you also send fragments to random addresses in China?
http//www.forensicfocus.com/Forums/viewtopic/t=9682/

jaclaz

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Posted : 16/10/2012 1:21 am
mscotgrove
(@mscotgrove)
Senior Member

I cut my CDs once and am happy that no one will read anything - but I also don't have anything on my CDs that I consider 'top secret'.

BUT, do you also send fragments to random addresses in China?
http//www.forensicfocus.com/Forums/viewtopic/t=9682/

jaclaz

No, they go to an address near Florence

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Posted : 16/10/2012 4:01 am
C.R.S.
(@c-r-s)
Active Member

BUT, do you also send fragments to random addresses in China?

It turned out that the maximum CD fragment size which I'm allowed to send to China is 10 mm².

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Posted : 16/10/2012 11:13 am
williamsonn
(@williamsonn)
Member

I think hmorgan's summary is good.

I am not sure what the original question is asking
Is it - can data be found
OR
Is it safe to cut CDs up and be happy that data will not be found.

.

Original question was about both if from a destroyed cd, dvd, or hdd (destroyed according description), can be in any way, recovered any kind of really significant data(texts -word, txt, pdf-, sound files -wav, mp3 etc-, image files, etc)from any user. That is not only bytes, but significant reconstructed information.

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Topic starter Posted : 18/10/2012 7:06 pm
jaclaz
(@jaclaz)
Community Legend

Original question was about both if from a destroyed cd, dvd, or hdd (destroyed according description), can be in any way, recovered any kind of really significant data(texts -word, txt, pdf-, sound files -wav, mp3 etc-, image files, etc)from any user. That is not only bytes, but significant reconstructed information.

Well, not really, original question was (IMHO) asked in such a way that excluded implicitly a number of possible answers

hello everyone
I would like to ask your opinion about if it is currently possible to recover and reconstruct not simple bits but significant user´s data from a cd or dvd with many (more than 10)rough scissors cuts from edge to center, when most pieces are present. Thanks.

What if you have only few (less than ten) scissors cuts?
What if the cuts are neat (as opposed to rough)?
What if ALL pieces are present?
What if few (as opposed to most) pieces are present?

The answer is that - at the state of the art - (and EXCLUDED what the National Security Agencies may have in their secret labs) a single, neat or rough, cut through a CD/DVD, passing through the center hole and thus dividing the CD in two pieces is enough, even if you have both pieces, to avoid the reading of any data from it with any commercially available device.
This doesn't mean that it is "impossible", only that noone has ever documented the successful recovery of any data from such a damaged CD/DVD.

In theory, it is perfectly possible - excluded the actual minimal data residing in the immediate nearness of the single cut - but in practice the tools/devices needed to perform such a recovery do not exist (with the previously stated caveat about Government Agencies), and developing such a device is not exactly one of those hacks you do in your garage in your spare time.

Two pieces are enough, three or four are "better", more cuts (and thus smaller pieces) may only be needed due to the postage limits (when you send them to random addresses wink ).

jaclaz

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Posted : 18/10/2012 7:50 pm
williamsonn
(@williamsonn)
Member

quote="jaclaz"]

- williamsonn

The answer is that - at the state of the art - (and EXCLUDED what the National Security Agencies may have in their secret labs)

Two pieces are enough, three or four are "better", more cuts (and thus smaller pieces) may only be needed due to the postage limits (when you send them to random addresses ).

jaclaz

From all your previous answers, it seems that it is not possible to recover such destoyed devices´information, not even in court trials, and that only perhaps, might be possible, using certain supposed secret tecniques used by national agencies. Then I wonder are not these supposed special techniques used in trials? If not, then couldn´t these tecniques be speculation?

On the other hand, I suppose it is irony what´s the exact meaning of the last phrase "more cuts (and thus smaller pieces) may only be needed due to the postage limits (when you send them to random addresses"? Thanks

williamsonnNewbie

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Topic starter Posted : 19/10/2012 5:46 am
jaclaz
(@jaclaz)
Community Legend

You should check my signature.

And check this other thread (already linked to in a previous post on this same thread that you possibly missed) to understand the reference to the mail
http//www.forensicfocus.com/Forums/viewtopic/t=9682/

The idea of something (IF it exists) being secret, is that noone (exception made for those allowed to) know anything about it.
Is such a device technically and theoretically possible? Yes.
Could it exist and be a secret? Yes.
Does it actually exist and it is NOT a secret? No.
Does it actually exist and it IS a secret? Who knows?, it's a secret.
Why a secret device (IF it exists) is not used in public trials? Because after it's use in a public trial it wouldn't be secret anymore.

Here is some actual research
http//www.thic.org/pdf/Jun04/UniversityOfArizona.Milster-2-%20Data%20Recovery%20from%20CD-R%20Fragments%20rev%20a.pdf

jaclaz

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Posted : 19/10/2012 11:51 am
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