Say I have a file I want to erase. Simply deleting it is not enough. It still resides in the recycle bin. Emptying the recycle bin does little as well, the actual data is not deleted just the pointer, this means that as long as the file is not overwritten the data is still recoverable. Lets say I have a file I want to completely delete and hide the contents of. Before deleting the file. I open the file and remove all the content inside it and replace it with a series of zeros.
So a file like this:
THIS IS SOME SAMPLE TEXT
Turns into this:
When I delete the file after replacing everything with zeros is the original data(THIS IS SOME SAMPLE TEXT) gone? The pointer is gone and the series of zeros is still on the disk but is actually still possible to recover those zeros and figure out that before those zeros were there the original data was "THIS IS SOME SAMPLE TEXT"? If not would that original piece of data be erased without any hope of recovery? If the data can still be recovered, whats the best way of erasing it so that its hardest for anyone to recover it through digital forensic tools?