Method Name | Number of Passes | Description |
Pseudorandom data | 1 | The fastest wiping scheme. Your data is overwritten with random data (if you use a CSPRNG the data is indistinguishable from random noise.) |
British HMG IS5 (Baseline) (1 pass) | 1 | Your data is overwritten with zeroes. |
Russian GOST P50739-95 | 2 | GOST P50739-95 wiping scheme calls for a single pass of zeroes followed by a single pass of random data |
British HMG IS5 (Enhanced) | 3 | British HMG IS5 (Enhanced) is a three pass overwriting algorithm: first pass – with zeroes, second pass – with ones and the last pass with random data. |
US Army AR380-19 | 3 | AR380-19 is data wiping scheme specified and published by the U.S. Army. AR380-19 is three pass overwriting algorithm: first pass – with random data, second with a random byte and the third pass with the complement of the 2nd pass |
US Department of Defense DoD 5220.22-M (E) | 3 | DoD 5220.22-M (E) is a three pass overwriting algorithm: first pass – with zeroes, second pass – with ones and the last pass – with random data |
US Air Force 5020 | 3 | US Air Force 5020 is a three pass overwriting algorithm with the first pass being that of a random byte, followed by two passes of complement data (shifted 8 and 16 bits right respectively) |
US Department of Defense DoD 5220.22-M(ECE) | 7 | DoD 5220.22-M(ECE) is seven pass overwriting algorithm: first, fourth and fifth pass with a random byte, its 8 right-bit shift complement and 16 right-bit shift complement; second and sixth passes with zeroes, and third and seventh pass with random data |
Canadian RCMP TSSIT OPS-II | 7 | RCMP TSSIT OPS-II is a seven pass overwriting algorithm with three alternating patterns of zeroes and ones and the last pass – with a random byte |
German VSITR | 7 | The German standard calls for data to be overwritten with three alternating patterns of zeroes and ones and in the last pass with random data |
Schneier’s Algorithm | 7 | The Bruce Schneier algorithm has seven passes: first pass – with ones, the second pass – with zeroes and then five times with random data |
Random Data vs. Random Byte: Random data is continually generated, a random byte is a randomly generated number, and that number is repeated throughout the pass.