Main page
personal information


Data stored on magnetic disk media can be recovered using sophisticated analysis techniques. This means that, for example, even if some your old file was overwritten by new data, maybe it's still recoverable. Overwrite is a UNIX utility that try to make harder data recovering. What overwrite does is to overwrite files using random patterns and deterministic patterns, as suggested in the Peter Gutmann's paper "Secure Deletion of Data from Magnetic and Solid-State Memory".


There are no proofs about the fact that overwrite works, I'm just able to check that overwrite is able to overwrite the files with specific patterns but I've no proofs that this makes the data harder to be recovered. Also it's possible that if you use some type of hard-disk, file system, operative system, overwrite will NOT able to overwrite the file correctly. Use it at your risk.


This software is under the GPL license

Download Overwrite

The latest overwrite release is the 0.1.5
You can download the source code here.


Peter Gutmann's paper :ovewrite is based on this paper.
Mcrypt :a replacement of the old unix crypt(1).
AES official site :the Advanced Encryption Standard site.
Counterpane labs :the Counterpane labs, here you can find good patent-free crypto algorithm.
Handbook of Applied Cryptograpy :a good book about cryptography downloadable for free.
Crypto Author Sites :links to cryptography authors' homepages and sites where their publications may be found (page of

last update: Sun Dec 17 02:07:23 CET 2000