Provided by: secure-delete_3.1-6ubuntu1_amd64 bug

NAME

       srm - secure remove (secure_deletion toolkit)

SYNOPSIS

       srm [-d] [-f] [-l] [-l] [-r] [-v] [-z] files

DESCRIPTION

       srm  is designed to delete data on mediums in a secure manner which can
       not be recovered by thieves, 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 srm 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.

       *      Rename the file to a random value

       *      Truncate the file

       As an additional measure of security, the file is opened in O_SYNC mode
       and after each pass an fsync() call is done.  srm writes 32k blocks for
       the  purpose  of speed, filling buffers of disk caches to force them to
       flush and overwriting old data which belonged to the file.

COMMANDLINE OPTIONS

       -d     ignore the two special dot files . and ..  on  the  commandline.
              (so you can execute it like "srm -d .* *")

       -f     fast (and insecure mode): no /dev/urandom, no synchronize mode.

       -l     lessens the security. Only two passes are written: one mode with
              0xff and a final mode random values.

       -l     -l for a second time lessons the security even  more:  only  one
              random pass is written.

       -r     recursive mode, deletes all subdirectories.

       -v     verbose mode

       -z     wipes the last write with zeros instead of random data

LIMITATIONS

       NFS    Beware of NFS. You can't ensure you really completely wiped your
              data from the remote disks.

       Raid   Raid Systems use stripped disks and have got large caches.  It's
              hard to wipe them.

       swap, /tmp, etc.
              Some  of  your  data  might  have  a  temporary  (deleted)  copy
              somewhere on the disk. You should use sfill which comes with the
              secure_deletion   package  to  ensure  to  wipe  also  the  free
              diskspace. However, If already a small  file  acquired  a  block
              with  your precious data, no tool known to me can help you here.
              For a secure deletion of the swap space sswap is available.

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

       srm  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

       sfill (1), sswap (1), sdmem (1)

                                                                        SRM(1)