Details on the old Canadian data wipe method

Picture of a top secret document being shredded in a paper shredder

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RCMP TSSIT OPS-II is a software-based data sanitization method used in various file shredder and data destruction programs to overwrite existing information on a hard drive or another storage device.

Erasing a hard drive using the RCMP TSSIT OPS-II data sanitization method will prevent all software based file recovery methods from finding information on the drive and is also likely to prevent most hardware-based recovery methods from extracting information.


Some data sanitization methods will overwrite all the data with just zeros, like Write Zero. Others may use ones as well like Secure Erase, while some data wipe methods use random characters like with the Random Data and Gutmann methods.

RCMP TSSIT OPS-II combines these methods and is usually implemented in the following way:

  • Pass 1: Writes a zero
  • Pass 2: Writes one
  • Pass 3: Writes a zero
  • Pass 4: Writes one
  • Pass 5: Writes a zero
  • Pass 6: Writes one
  • Pass 7: Writes a random character and verifies the write

The RCMP TSSIT OPS-II data sanitization method is usually correctly used as we show above, but we've also seen it implemented with random characters in place of some of the zero/one repeating passes in some programs.

What's meant by verifying the write on Pass 7 is just that the software that's using the data sanitization method will check that the storage device has actually been overwritten with random characters - the DoD 5220.22-M method does this after every single one of its passes. A verify pass will normally repeat itself if the verification check fails.

Many programs that support the RCMP TSSIT OPS-II wipe method will let you run the above sequence multiple times. That means after writing all the ones and zeros and then finishing with random characters, the application will just start back over from the beginning and continue to do that for however many repeats you've selected.

Programs That Support RCMP TSSIT OPS-II

If you want to erase all the files on a storage device using the RCMP TSSIT OPS-II method, we recommend the free DBAN program. Software that runs while an operating system is currently being used can not erase that same hard drive (because many files are locked and can't be deleted), but DBAN is different in that it launches before the OS, and so must run from a CD or USB device.

Delete Files Permanently is a free file shredder tool that lets you delete any specific file or group of files using the RCMP TSSIT OPS-II sanitization method.

The program Eraser is another application that supports this data wipe method. It can be used to delete an entire hard drive like other data destruction programs, but can also be used to delete just single files and folders.

BCWipe and WipeDrive aren't free but they support this same data wipe method, too.

Most programs like these support multiple data sanitization methods in addition to RCMP TSSIT OPS-II. So if you'd like, you could actually choose a different method once you've started using the program, or even use another data wipe method before or after running RCMP TSSIT OPS-II.


The RCMP TSSIT OPS-II sanitization method was originally defined in Appendix Ops-II: Media Sanitation of the Technical Security Standards for Information Technology document, published by the Royal Canadian Mounted Police (RCMP). It's available here as a PDF.

However, RCMP TSSIT OPS-II is no longer the Canadian government's software-based data sanitization standard. The data sanitization standard in Canada is now CSEC ITSG-06 or a program that utilizes Secure Erase.

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