---
name: "smem"
section: "1"
platform: "linux"
package: "secure-delete"
version: "3.1-4"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/smem"
---

# smem(1)

secure memory wiper (secure\_deletion toolkit)

## NAME

smem - secure memory wiper (secure\_deletion toolkit)

## SYNOPSIS

**smem \[-f\] \[-l\] \[-l\] \[-v\]**

## DESCRIPTION

*smem* is designed to delete data which may lie still in your memory (RAM) in a secure manner which can not be recovered by thiefs, law enforcement or other threats. Note that with the new SDRAMs, data will not wither away but will be kept static - it is easy to extract the necessary information! 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 smem goes like this:

- **\***

  1 pass with 0x00

- **\***

  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.

## COMMANDLINE OPTIONS

- **-f**

  fast (and insecure mode): no /dev/urandom.

- **-l**

  lessens the security. Only two passes are written: the first with 0x00 and a final random one.

- **-l**

  \-l for a second time lessons the security even more: only one pass with 0x00 is written.

- **-v**

  verbose mode

## BEWARE

- **SLOW**

  Wiping the memory is very slow. You might use smem with the -ll option. (tip)

- **BETA!**

  *smem* is still beta.

## BUGS

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 :)

## AUTHOR

van Hauser / THC *\<vh@thc.org\>*

## DISTRIBUTION

The newest version of the *secure\_deletion package* can be obtained from  *http://www.thc.org*

*smem* and the *secure\_deletion package* is (C) 1997-2003 by van Hauser / THC (vh@thc.org)

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.

## SEE ALSO

*srm* (1), *sfill* (1), *sswap* (1)