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QuestionRe: Rename Pin
Rajesh R Subramanian26-Feb-08 20:45
professionalRajesh R Subramanian26-Feb-08 20:45 
GeneralRe: Rename Pin
john563226-Feb-08 20:47
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GeneralRe: Rename Pin
Rajesh R Subramanian26-Feb-08 20:51
professionalRajesh R Subramanian26-Feb-08 20:51 
GeneralRe: Rename Pin
john563226-Feb-08 20:59
john563226-Feb-08 20:59 
GeneralRe: Rename Pin
Rajesh R Subramanian26-Feb-08 21:42
professionalRajesh R Subramanian26-Feb-08 21:42 
GeneralRe: Rename Pin
Rajkumar R26-Feb-08 20:54
Rajkumar R26-Feb-08 20:54 
GeneralRe: Rename Pin
john563226-Feb-08 21:19
john563226-Feb-08 21:19 
NewsRe: Rename Pin
James R. Twine27-Feb-08 1:15
James R. Twine27-Feb-08 1:15 
pther wrote:
I want to erase the file content so that file could not be recover i.e completely destroyed from the system.


   To do that correctly takes quite a bit of know-how.  It is not as simple as just filling a file with one pass of random data (which, BTW, is more secure than using just zeros because the bit patterns are different) and then deleting the file.

   Without even getting into issues like how magnetic media works and how "underlying" bit patterns can be recoverable using really expensive equipment (see: Peter Gutmann's paper on this[^]), simple things like the OS cache, and disk cache will interfere greatly.

   For example, just because you wrote 1MB of data in code does not mean that it has made its way to disk (yet).  It could hang around in the OS cache, and then in the disk cache.  If you write the same file location multiple times (i.e. you were trying multiple write passes with different random data like you should), the disk might not get any of the writes except the last one.

   You really need to research how caches work in your target OS as well as on disk drives, and then how modern magnetic storage works before going down this path.  Tip - you will at least have to learn about which different bit patterns to write and how many times they need to be put on the media.

   Why do I know this?  Because I have written "secure deletion" software before, and debunked other so-called secure deletion programs as part of for-hire research (quite a few years ago and no, I cannot say the company).  Today's drives may work a lot different than the ones I worked with before, so things may be even more difficult these days.

   I will say that much of the "security" software out there do nothing more than offer a false sense of security.

   Peace!

-=- James
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GeneralRe: Rename Pin
Expert Coming26-Feb-08 20:47
Expert Coming26-Feb-08 20:47 
GeneralRe: Rename Pin
john563226-Feb-08 20:50
john563226-Feb-08 20:50 
GeneralRe: Rename Pin
Maxwell Chen26-Feb-08 21:29
Maxwell Chen26-Feb-08 21:29 
GeneralRe: Rename Pin
Rajkumar R27-Feb-08 18:10
Rajkumar R27-Feb-08 18:10 
QuestionHow to use..._commit() Pin
john563226-Feb-08 20:13
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AnswerRe: How to use..._commit() Pin
Rajkumar R26-Feb-08 20:25
Rajkumar R26-Feb-08 20:25 
GeneralRichEdit control Pin
ShilpiP26-Feb-08 20:01
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GeneralRe: RichEdit control [modified] Pin
Rajesh R Subramanian26-Feb-08 20:15
professionalRajesh R Subramanian26-Feb-08 20:15 
GeneralRe: RichEdit control Pin
ShilpiP26-Feb-08 20:25
ShilpiP26-Feb-08 20:25 
GeneralRe: RichEdit control Pin
Rajkumar R26-Feb-08 20:30
Rajkumar R26-Feb-08 20:30 
GeneralRe: RichEdit control Pin
ShilpiP26-Feb-08 20:41
ShilpiP26-Feb-08 20:41 
GeneralRe: RichEdit control Pin
Rajesh R Subramanian26-Feb-08 20:54
professionalRajesh R Subramanian26-Feb-08 20:54 
GeneralRe: RichEdit control Pin
ShilpiP26-Feb-08 21:06
ShilpiP26-Feb-08 21:06 
GeneralRe: RichEdit control Pin
Rajesh R Subramanian26-Feb-08 21:16
professionalRajesh R Subramanian26-Feb-08 21:16 
GeneralRe: RichEdit control Pin
Rajesh R Subramanian26-Feb-08 20:37
professionalRajesh R Subramanian26-Feb-08 20:37 
GeneralRe: RichEdit control Pin
ThatsAlok26-Feb-08 20:28
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ShilpiP26-Feb-08 21:08
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