The Gutmann Method is a an algorithm for securely erasing the contents of a computer hard drive. Introduced by Peter Gutmann in 1996, it utilizes a series of 35 patterns to completely and redundantly overwrite the contents of a hard disk. The method, and the white paper in which Gutmann outlined its use, was widely misapplied and misinterpreted–although many people used the full 35-pass technique, Gutmann never intended for the method to be used from start to finish in such a fashion.
At the time the method was introduced, it included several features that are no longer necessary or relevant for secure file erasure. The 35 passes include patterns intended to wipe out data structures that are no longer used, for example, and further research into data recovery has shown that even a single pass or two of zeros over a hard drive renders it unrecoverable (the Department of Defense only uses 7 passes in its most intensive wipe, quite a bit less than 35 many people mistakenly used with the Gutmann Method.)
For more reading on secure disk erasure, reference HTG Explains: Why You Only Have to Wipe a Disk Once to Erase It.
- By Jason Fitzpatrick on 10/16/13