posted on Oct, 18 2003 @ 11:46 AM
If you do not want to destroy the drive, and just want to delete the deleted, several things must be considered.
1-when you delete something, it's still there, as mentioned. Just un-associates with the OS.
2- If you do a format or some type of erase, then it it is gone, but still can be magnetically retrieved via the underlayers. Magnetic media, has a
strange characteristic to be written down into the layers. Lets say you write over something, your system is trained to read what is on top. But the
media can still be read below that layer. The feds do this to retrive what has been recorded on a tape, and then recorded over. Using error correction
software, the previous write can be discerned via software.
So if you want to wipe it clean, the following must be done. The DoD had a policy on such, and some freeware was available sometime back for us
It is a seven pass, cross-interleave, wipe and write of random data.
The seven pass was determined to effectively go down to the lower layers, which would normally be just written on, and still existed otherwise.
The cross interleave on a seven pass, means that the data written 'crosses over' in such a fashion that it would not be recognisable in a stream.
You would have to know the exact interleave pattern to be able to read back.
The random, well self explanitory, written seven times over in a cross interleave pattern, would prove very difficult for any software to read any
Software like a DoD wiper is available, some as freeware, do a search.