The RCMP TSSIT OPS-II data sanitization method 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 I show above but I've seen it implemented with random characters in place of some of the zero/one repeating passes in some programs.
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.
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).
Note: 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. Information about Canada's data sanitization standards can be found on the Royal Canadian Mounted Police website here.
Most data destruction programs support multiple data sanitization methods in addition to RCMP TSSIT OPS-II.