Question about eraser type programs
by TONI H - 11/18/05 1:10 PM
If I use a file-shredder or an eraser type program on the free space of a harddrive, and those programs have an option for the number of 'wipes' with ones and zeros, I'm not sure I'm understanding what it's doing and thought maybe since this is a 'security' forum, somebody else might be able to tell me.
I have an empty drive partition that has a 'recycle' bin on it but nothing else. Not even a 'system information' folder for restores. It's 22GB in size and had all files that were on it either moved directly to another partition or copied to another partition and the folder structure mutilated prior to using the eraser program.
Once the first shredder program was used, I used another Undelete program to see what was recoverable on the drive as a test before 'erasing' the drive with the third program. I found many files with the undelete program that although the files were zero bytes and unrecoverable, the file names were still showing up exactly as they were before.
I then ran the eraser program. After it was finished, I used the undelete program again to check and found that now all the files were named with a question mark, zero bytes, and the modified date was also all zeros as 00/00/0000 and unrecoverable.
You (or at least I) would think that if everything was actually 'erased' that the undelete program would find NOTHING...not file names of ?....correct? Otherwise it would seem that because there is SOMETHING still there enough for the undelete program to find, then wouldn't it stand to reason that somebody out there with sophisticated enough programs could actually get into those ? files enough to get bits and pieces and identify what parts of the original files they represent?
Would low-level format software be used instead on the free space of a partition? Would it have to wipe the entire partition or would it have to involve the entire harddrive and cannot be selective with regard to partitioning? If low-level format programs write all zeros as I've been told, what does the eraser type programs do since it writes ones AND zeros?