SDMEM(1)

📦 version 3.1, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 SDMEM(1) — the secure memory wiper bestie 💖

okay so this is the manual page for sdmem, part of the secure_deletion toolkit, and it lives in the General Commands Manual. she's here to wipe your RAM and she is not playing around. let's get into it 🫶

✨ NAME ✨

sdmem — secure memory wiper (secure_deletion toolkit) 🧠💥

✨ SYNOPSIS ✨

sdmem [-f] [-l] [-l] [-v]

(yes the -l shows up twice, that's on purpose, more on that below 👀)

✨ DESCRIPTION ✨

so sdmem is literally designed to delete data that might still be chilling in your memory (that's RAM btw) in a secure way that can not be recovered by thieves, law enforcement, or other threats. no cap. 🕵️♀️

⚠️ and here's the tea: with the new SDRAMs, data will not wither away — it stays static. meaning it's easy to extract the necessary information! so like, don't sleep on this.

the wipe algorithm 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, who is one of the leading civilian cryptographers. iconic honestly. 👑

the secure data deletion process of sdmem 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.

that's the whole routine. 1 + 5 + 27 + 5, do the math bestie 🍓

✨ COMMANDLINE OPTIONS ✨

  • -f — fast (and insecure mode): no /dev/urandom. 💀 yeah it's fast but it's insecure, the name is right there.
  • -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. 😭 stacking them makes it weaker, not stronger, okay?? pay attention.
  • -v — verbose mode 🌸

✨ NOTE ✨

this utility was originally called smem but was renamed for debian to avoid name clashes with another package. glow-up rebrand fr fr 💅

✨ BEWARE ✨

  • SLOW — wiping the memory is very slow. You might use sdmem with the -ll option. (tip) 🐌
  • BETA! — sdmem 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 🌈

sdmem 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)

and that's the whole page bestie 💜 this one's sdmem(1) from the General Commands Manual — go forth and wipe that memory, stay secure, and remember: -l twice means less security, not more. mwah 🎀✨

📦 where this page comes from