sswap(1) secure swap wiper (secure_deletion toolkit)


sswap [-f] [-l] [-l] [-v] [-z] swapdevice


sswap is designed to delete data which may lie still on your swapspace in a secure manner which can not be recovered by thiefs, law enforcement or other threats. The wipe algorythm is based on the paper "Secure Deletion of Data from Magnetic and Solid-State Memory" presented at the 6th Usenix Security Symposium by Peter Gutmann, one of the leading civilian cryptographers.

The secure data deletion process of sswap goes like this:

1 pass with 0xff
5 random passes. /dev/urandom is used for a secure RNG if available.
27 passes with special values defined by Peter Gutmann.
5 random passes. /dev/urandom is used for a secure RNG if available.


fast (and insecure mode): no /dev/urandom, no synchronize mode.
lessens the security. Only two passes are written: one mode with 0xff and a final mode with random values.
-l for a second time lessons the security even more: only one pass with random values is written.
verbose mode
wipes the last write with zeros instead of random data


unmount your swapspace before using this tool! Otherwise your system might crash!
sswap is still beta. It was only tested on Linux but on this system it performed it's work all of the time.


No bugs. There was never a bug in the secure_deletion package (in contrast to my other tools, whew, good luck ;-) Send me any that you find. Patches are nice too :)


van Hauser / THC <[email protected]>


The newest version of the secure_deletion package can be obtained from

sswap and the secure_deletion package is (C) 1997-2003 by van Hauser / THC ([email protected])

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; Version 2.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.