[Delphi] Eliminator - Data Shredder & Wiper
 

Final release of open source Data Shredder that called "Eliminator", supports 4 type of shredding and added free space wipe feature.
tested with several 1 & 2 TB hard disk to wipe information and attempt to recovery, all of test was unsuccessful in data recovery.
I changed "grinder" name to "eliminator" because there is some app with name similarity that have porno uses !

access full source code

https://github.com/NIKJOO/FastShredder

I've tested many tools who wipe data onto hd's,filling 0 or random data but even with at single wipe i've never met any tools who recovered them and trust me I've used many ones,what you suggest to test a deeper recovery able to recover a full 0 fill onto a hd?

I suggest to test these ones

1.Active File Recovery
2.Recuva Professional
3.GetDataBack Pro Data Recovery

And you're right... no such software tool exists, once overwritten that bit is gone, no matter what value was written(0 or 1) there's no way to determine the previous one. Sure, if it makes one feel better, he can fill multiple times, usign whatever patterns... but same result as a simple fill with 0x00 or 0xff, security wise I see no improvement.
This thing of someone being able to recover previous data from a classic hard disk that was overwritten in whatever form is just a sort of a myth, nothing to back it up, especially these days, when the density is at the level it is, I can only imagine the sort of hardware they should have in order to measure the residuals, if any and even then, what is noise and what is something? This story (recover overwritten data through hardware means, microscopes and stuff) started many years ago, when Peter Gutmann claimed, just theoretically, that this could be possible, decades after some still hang on that, though no evidence that this was ever done, before or even to this day.
Some even claim that they can recover through software tools/means the overwritten data... with basic knowledge of how the data is stored in a hard disk you know already what to think of that.
A nice lecture on this topic...

For any real progress you'd need hardware based tools. These are available generally only to state level actors. They make use of residual magnetic hysteresis and other phenomena for recovery of the data bits.

Software-based tools rarely work and and even when they do work it is only for data that has been deleted very, very recently, where nothing has overwritten the original bits.

Correct, you need speciality hardware to retrieve the very low remnant magnetic signal from the HD heads. Some small residue of the original data can exist even after some wiping cycles, but it gets almost impossible to recover it after just a few random overwrites. Check out the DoD standard for what they deem adequate. Some special services used to have an X marked on the back of their laptops, as an aiming point for you trusty 9mm, alledgedly :).

I agree with your comments, my shredder do same thing as you said , overwriting data with random pattern except verification pass ( this pass was really time-consuming and end-user annoying )

Thanks to all,i suspected it was a myth,not even wiping data with 0,in case of rude crash,something who corrupted usual system files are soften hard to recover,big size hd's we have now are worst in time of recovery time.
@ Gladiyator:anyway,respect for your work and sharing it,it were not any critics from me.

The software based tools are useful in cases of accidental formatting of the drives. The "oops" moment after you discover that you formatted the wrong drive. :D
In such cases if you just remove the hard drive and try to recover on another machine, the tools work ok...