Erase Hard Disk
Wipe Parameters

6. Erase/Wipe Parameters and Application Settings

Whether you choose to erase data from the drive or to wipe data from unoccupied drive space, the methods of overwriting over these spaces are the same.

6.1 Erase/Wipe Methods

1 - One Pass Zeros or One Pass Random

When using One Pass Zeros or One Pass Random, the number of passes is fixed and cannot be changed. When the write head passes through a sector, it writes only zeros or a series of random characters.

2 - User Defined

You indicate the number of times the write head passes over each sector. Each overwriting pass is performed with a buffer containing the pattern you specified (ASCII string).

3 - US DoD 5220.22-M

The write head passes over each sector three times. The first time is with zeros (0x00), the second time with 0xFF and the third time with random characters. There is one final pass to verify random characters by reading.

4 - US DoD 5220.22-M (ECE)

The write head passes over each sector seven times (0x00, 0xFF, Random, 0x96, 0x00, 0xFF, Random). There is one final pass to verify random characters by reading.

5 - Canadian OPS-II

The write head passes over each sector seven times (0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, Random). There is one final pass to verify random characters by reading.

6 - German VSITR

The write head passes over each sector seven times . (0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0xAA). There is one final pass to verify random characters by reading.

7 - Russian GOST p50739-95

The write head passes over each sector two times. (0x00, Random). There is one final pass to verify random characters by reading.

8 - US Army AR380-19

The write head passes over each sector three times. The first time with 0xFF, second time with zeros (0x00) and the third time with random characters. There is one final pass to verify random characters by reading.

9 - US Air Force 5020

The write head passes over each sector three times. The first time with random characters, second time with zeros (0x00) and the third time with 0xFF. There is one final pass to verify random characters by reading.

10 - HMG IS5 (Baseline and Enhanced)

Baseline method overwrites disk's surface with just zeros (0x00).

Enhanced method - the write head passes over each sector three times. The first time with zeros (0x00), second time with 0xFF and the third time with random characters.

There is one final pass to verify random characters by reading.

11 - Navso P-5329-26 (RL and MFM)

RL method - the write head passes over each sector three times (0x01, 0x27FFFFFF, Random).

MFM method - the write head passes over each sector three times (0x01, 0x7FFFFFFF, Random).

There is one final pass to verify random characters by reading.

12 - NCSC-TG-025

The write head passes over each sector three times (0x00, 0xFF, Random). There is one final pass to verify random characters by reading.

13 - NSA 130-2

The write head passes over each sector two times (Random, Random). There is one final pass to verify random characters by reading.

14 - Bruce Schneier

The write head passes over each sector seven times (0xFF, 0x00, Random, Random, Random, Random, Random). There is one final pass to verify random characters by reading.

15 - Gutmann

The write head passes over each sector 35 times. For details about this, the most secure data clearing standard, you can read the original article at the link below: www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html