Erase Hard Disk
Wipe Parameters

6. Descriptions of Erase/Wipe Parameters

Whether you choose to erase data from the drive or to wipe data from unoccupied drive space, the methods of writing over these spaces is 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 and pattern to be written.

3 - US DoD 5220.22-M

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.

4 - US DoD 5220.22-M (ECE)

The write head passes over each sector seven times. The first time with zeros (0x00), second time with 0xFF and the third time with random characters, the fourth time with 0x96, and then first three passes repeated again. There is one final pass to verify random characters by reading.

5 - German VSITR

The write head passes over each sector seven times, each pass writing the following characters: 0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, 0xAA.

6 - Russian GOST p50739-95

The write head passes over each sector two times, first pass is zeroes (0x00), the second pass is random characters.

7 - Canadian OPS-II

The write head passes over each sector seven times, each pass writing the following characters: 0x00, 0xFF, 0x00, 0xFF, 0x00, 0xFF, Random.

8 - HMG IS5 Baseline

The write head passes over each sector once, writing zeroes (0x00).

9 - HMG IS5 Enhanced

The write head passes over each sector three times, writing zeroes (0x00), then 0xFF, and finally random characters.

10 - US Army AR380-19

The write head passes over each sector three times, first pass writing random characters, then zeroes (0x00), and finally 0xFF.

11 - US Air Force 5020

The write head passes over each sector three times, first pass writing 0xFF, then zeroes (0x00), and finally random characters.

12 - Navso P-5329-26 RL

The write head passes over each sector three times, first pass writing 0x01, then 0x27FFFFFF, and finally random characters.

13 - Navso P-5329-26 MFM

The write head passes over each sector three times, first pass writing 0x01, then 0x7FFFFFFF, and finally random characters.

14 - NCSC-TG-025

The write head passes over each sector three times, first pass writing zeroes 0x00, then 0xFF, and finally random characters.

15 - Bruce Schneier

The write head passes over each sector seven times, each pass writing the following characters: 0xFF, zeroes (0x00), then five passes with random character.

16 - 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.