What is the difference between the Format, 1-pass, 3-pass, and 7-pass options in the MetaDefender Kiosk wipe functionality?

All of these options delete all of the files on the selected media. However, some of the methods are more secure because they make it harder for data to be recovered using specialized tools that can read the remnants of files that were previously on the disk.

Format is the fastest option, but it simply removes the references to the files on the drive without overwriting those portions of the drive. The 1, 3, and 7 pass wipe options write over the entire drive with differing algorithms, making it much more difficult to retrieve the data that was originally stored on the drive. The only way to fully erase the hard drive is to write over it using the wipe feature. The 1, 3 or 7 option lets you choose how many passes you wish to do. The United States Department of Defense recommends using a 7 pass wipe to clean media. OPSWAT does a low-level sector by sector wipe of the media.

WARNING: Using the wipe feature will completely erase and reformat ALL information on the device. This includes the partition table and master boot record along with any file system information.

Algorithm Details

Num. of Passes

Algorithm Steps in Order

Security Standard


  1. Pseudorandom

  • British HMG Infosec Standard 5, Baseline Standard

  • Australian Government ICT Security Manual 2014 - Controls


  1. All 1's

  2. All 0's

  3. Pseudorandom

  • U.S. DoD Unclassified Computer Hard Drive Disposition*

  • U.S. Air Force System Security Instruction 5020**

  • U.S. Navy Staff Office Publication NAVSO P-5239-26

  • British HMG Infosec Standard 5, Enhanced Standard

*We select 0xFF and 0x00 (reverse of standard), then pseudorandom data instead of a fixed character for our final pass


  1. All 1's

  2. All 0's

  3. Pseudorandom

  4. Pseudorandom

  5. Pseudorandom

  6. Pseudorandom

  7. Pseudorandom

  • Bruce Schneier's Algorithm: Applied Cryptography, ISBN 0-471-12845-7

If a device has a private or encrypted partition, systems may not be able to read it. Non-primary encrypted partitions can be blocked in the MetaDefender Kiosk Management Console. If a drive does not have any readable partitions, we recommend using the wipe functionality to clean the drive and ensure that there are no hidden partitions.

This article pertains to MetaDefender Kiosk
This article was last updated on 2019-10-09