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Ever reported data recovering from broken CD/DVD/HDD?

Computer forensics discussion. Please ensure that your post is not better suited to one of the forums below (if it is, please post it there instead!)
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Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 2:01 pm

Why do you get angry, jaclaz? Very Happy

surely I don´t expressed correctly or perhaprs you dont understand me. I just asked if I can know,recognize which of the 3 categories you stated fits any specific hard drive, for example the old ones I have.  

williamsonn
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 2:30 pm

The sense of that quesion is simply curiosity.

By the way, one of your replies to my first yjread on the question you say:

" 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."

However at the same study whose link you posted, the author seems to have recovered significant information from CD fragments(unless I had not understood correctly the article).  

williamsonn
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 2:53 pm

I think jaclaz has ever right 'sound angry'

He gave you typical dates for drives. I think every drive I have seen has a date on it. What more information do you need?

As for CDs, this was discussd at length on your previous posting, some time ago.

My question is why are you asking the questions.

1) Do you wish to recover such data - what budget do have for such attempts?

or

2) You have data you want to destroy and make sure no one else can ever read it?
_________________
Michael Cotgrove
www.cnwrecovery.com
cnwrecovery.blogspot.com/ 

mscotgrove
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 3:15 pm

I suggest the OP carry out a bit of an experiment with a CD.

To the OP...

Take one and snap in half with your hands ( wear gloves! ). You will see that the substrate ( that's the silver material ) will pulverize along the fracture lines into a lot of little pieces. I don't know how you could re-assemble a useable readable CD from these tiny fragments. As for HDD with a hole drilled in it, I doubt a drive head would survive passing over the resulting burrs.

I think if the OP does some observation of the physical properties of a broken ( not scored ) optical disk he will see what Jaclaz is getting at.  

Beetle
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 3:41 pm

- williamsonn
Why do you get angry, jaclaz? Very Happy

Because I feel that at least big parts of the "sent messages" don't go through and never reach you.
- williamsonn

surely I don´t expressed correctly or perhaprs you dont understand me. I just asked if I can know,recognize which of the 3 categories you stated fits any specific hard drive, for example the old ones I have.

And you already asked a very similar question and you were already replied, you need to know, capacity, number of platters, derive areal density, cross-check with manufacturer specs when available, compare with year of production, verify with several different sources, then, you will be able to make an educated guess.

And of course there are many more than three categories - hence the concept of "simplified list".

Now try reading carefully and attentively the quoted sentence (of which I have highlighted some relevant parts that you seemingly missed):

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.


So. let's try again AFTER having ALREADY discussed in detail what "secret" means:
www.forensicfocus.com/...7/#6562637

Three points:
  1. What the G-men can (or cannot) do is SECRET (noone except them and a few other authorized people that will keep their mouth shut know exactly what they can do).
  2. There is NO commercially available device/method to recover data from a broken CD (again to the best of my knowledge).
  3. There is/was an experimental theory and an experimental project aimed to read data from a CD through imaging it with a microscope (and a link was given to the report about that research).
I hope there is no issue with items #1 and #2 above.

About #3, if you READ that document, you will possibly gather that (again main points, if you read it attentively you will find more) that the experiment was made on a non-broken CD, on page #16 "Present technique" is estimated at 67 year time to read a complete CD, what was written to the CD was not "random data", but it was a specific sized (very small) grey scaled bitmap (i.e. a non-encoded file that can be easily be represented partially if partial data is missing) forming a "pattern" repeated over and over (and they knew where this info was written to on the disk surface and conversely where to look at and also what to look for).
The CD used in the experiment is NOT broken into pieces.

That is a report about an EXPERIMENT that proves an UNDISPUTED theory (a media that is read through optical means may be read also through different optical means), but that besides the good results is NOWHERE representing a viable data recovery method.


IF - over the more than 8 (eight) years elapsed since - they have managed to reduce the time from actual 67 years to the hypothetical 475 hours (or less) AND IF *something else* is invented to "keep together" the pieces of a broken CD on the spin AND IF precision is bettered as to allow NO reading errors (and thus recover encoded data formats such as .jpg or .zip) AND IF this enhanced precision can be extended on a sensibly bigger data extent (the WHOLE SIZE of the file that was partially recovered was 11 Kb) AND IF this can be reproduced over several makes/models/brands of CD (both "pressed" and "burned") THEN they would have something that might develop into a commercial device (which costs I won't even dare to guess-estimate).

And in any case it would ALREADY be late, as the CD is not used anymore and DVD has a MUCH HIGHER data density (thus posing new issues).

jaclaz
_________________
- In theory there is no difference between theory and practice, but in practice there is. - 

jaclaz
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Sun Jan 20, 2013 7:27 pm

jaclaz. thanks for your patience and kindness, but not get angry, please Wink I appreciate much your interesting information. Now, ALL IS MUCH more clear for me.

Only a question more, please. Your last words are not totally clear for me:

"And in any case it would ALREADY be late, as the CD is not used anymore and DVD has a MUCH HIGHER data density (thus posing new issues)."

Do you mean that DVD recovering, more currenly used than CD, and having, of course much more density
Would be more difficult to read f broken, or, instead, easier?


Again, thank you very much Smile  

williamsonn
Senior Member
 
 
  

Re: Ever reported data recovering from broken CD/DVD/HDD?

Post Posted: Mon Jan 21, 2013 5:33 am

- williamsonn


Do you mean that DVD recovering, more currenly used than CD, and having, of course much more density
Would be more difficult to read f broken, or, instead, easier?


Let's temporarily forget about broken optical media.
Let's check your eyesight. Shocked
Following are two text lines, which one can you read more easily Wink ?
  1. This line represents some text written on a CD.
  2. This line represents the same line but written to a DVD.

But, when you go beyond the first impression (and get yourself a suitable magnifying glass to read the second line) you might want to consider how this also implies that you have to break DVD's in smaller pieces as a DVD fragment the same size you used to break CD's into may contain as much as 13 times the amount of information than a CD fragment.

jaclaz
_________________
- In theory there is no difference between theory and practice, but in practice there is. - 

jaclaz
Senior Member
 
 
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