deleting files
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Not sure if this goes here but I didnt want to post it in the lounge either. So here is the question. If I take a file and start reading through it as I look at each bit could I flip that bit? So if it is a 0 make it 1 ... ect? Here is what I want to do. Pass 1) Read through a file and reverse all the bits in the file Pass 2) Take the file and turn all bits off Pass 3) turn all bits on Pass 4) Delete the file Do you think this could allow me to securly delete a file from my system making it unrecoverable? Thanks Will
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Not sure if this goes here but I didnt want to post it in the lounge either. So here is the question. If I take a file and start reading through it as I look at each bit could I flip that bit? So if it is a 0 make it 1 ... ect? Here is what I want to do. Pass 1) Read through a file and reverse all the bits in the file Pass 2) Take the file and turn all bits off Pass 3) turn all bits on Pass 4) Delete the file Do you think this could allow me to securly delete a file from my system making it unrecoverable? Thanks Will
Not if someone is willing to dismantle the drive and use lab equipment to read residuals directely off the platter. The writehead only erases ~95% of the bit and it's movement over the platter afffects which part is missed so N passes won't erase 100*(1-.05^N) percent of the data. I've got a tool called BCWipe that uses a 35 pass algo designed by someone with initmate knowledge of how the HD writehead works that should render it unrecoverable. If you want to write your own program the used bit patterns are user view/editable. It also has an older 7pass DoD routine.
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Not sure if this goes here but I didnt want to post it in the lounge either. So here is the question. If I take a file and start reading through it as I look at each bit could I flip that bit? So if it is a 0 make it 1 ... ect? Here is what I want to do. Pass 1) Read through a file and reverse all the bits in the file Pass 2) Take the file and turn all bits off Pass 3) turn all bits on Pass 4) Delete the file Do you think this could allow me to securly delete a file from my system making it unrecoverable? Thanks Will
OMalleyW wrote: Do you think this could allow me to securly delete a file from my system making it unrecoverable? Definately not! After having visited the inside a computer forensics lab, I was surprised astonished at what you have to go through to stop these guys from getting at that data. What're suggesting on doing, really, is very weak. RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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OMalleyW wrote: Do you think this could allow me to securly delete a file from my system making it unrecoverable? Definately not! After having visited the inside a computer forensics lab, I was surprised astonished at what you have to go through to stop these guys from getting at that data. What're suggesting on doing, really, is very weak. RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
thanks for the reply's even if they could get to the file, the data is not recoverable... i guess that is really what I care about is the ability to get rid of data i dont really care if they can recover the file as long as the data is gone... any thoughts? will
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thanks for the reply's even if they could get to the file, the data is not recoverable... i guess that is really what I care about is the ability to get rid of data i dont really care if they can recover the file as long as the data is gone... any thoughts? will
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thanks for the reply's even if they could get to the file, the data is not recoverable... i guess that is really what I care about is the ability to get rid of data i dont really care if they can recover the file as long as the data is gone... any thoughts? will
OMalleyW wrote: even if they could get to the file, the data is not recoverable... First, there is no difference between the two. file=data You said you wanted a SECURE way to get rid of the data. Well, the way you suggested overwriting the data, it IS still recoverable. Not by your program or the file system, but by some hardcore tools and a little overtime in a lab... RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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OMalleyW wrote: even if they could get to the file, the data is not recoverable... First, there is no difference between the two. file=data You said you wanted a SECURE way to get rid of the data. Well, the way you suggested overwriting the data, it IS still recoverable. Not by your program or the file system, but by some hardcore tools and a little overtime in a lab... RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
Thank you again for the quick replies... Dan, I will look into BCWipe I read a little and it sounds very interesting. Currently I use SDelete from Sysinternals that is a cool program also. From what I understand (now) what I would like to write is no trivial task and will require me to do far more research. Dave, You mentoined that you were astonished at the tools the forensics lab had to get data. I guess I should also become more familar with the technologies that are used to recover data also. Thank you again for all your help. Will
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Thank you again for the quick replies... Dan, I will look into BCWipe I read a little and it sounds very interesting. Currently I use SDelete from Sysinternals that is a cool program also. From what I understand (now) what I would like to write is no trivial task and will require me to do far more research. Dave, You mentoined that you were astonished at the tools the forensics lab had to get data. I guess I should also become more familar with the technologies that are used to recover data also. Thank you again for all your help. Will
OMalleyW wrote: I will look into BCWipe I read a little and it sounds very interesting. Currently I use SDelete from Sysinternals that is a cool program also. From what I understand (now) what I would like to write is no trivial task and will require me to do far more research. If you want to actually design your own algorythm (bad idea!) you will, but to just implement it yourself is trivial. All you'd need to do is copy the bit patterns used and sequentially write each to the entire file. What would be nice would be a program that would also wipe 'underneath' existing files. It shouldn't be that hard to do either.