Security-related questions

Jonas Norlander jonorland at
Sat Apr 26 09:54:48 UTC 2008

2008/4/26 Nils Kassube <kassube at>:
>  Then perhaps don't use a special account, but put your sensitive data in a
>  file which looks like and really starts as a most boring but very long
>  video. However that video is corrupted in a way that after the first 5
>  minutes of the video it is overwritten by a virtual (encrypted) partition
>  file containing your data. If your sensitive data are on the (small)
>  partition /dev/sde3 of your external harddisk, you could get such a file
>  with these commands:
>  dd if=catvideo.mpg of=catsleepingonmylawn.mpg bs=10000000 count=1
>  sudo dd if=/dev/sde3 >>catsleepingonmylawn.mpg
>  Now if you want to access your sensitive data, use this mount command:
>  sudo mount -oloop,offset=10000000 catsleepingonmylawn.mpg /mnt
>  where 10000000 is the offset in bytes where the virtual partition starts,
>  i.e. the value for the "bs=" option of the dd command above. Use
>  something you can easily remember, then you don't need to have that info
>  written somewhere on your harddisk. And don't forget to clean the file
>  $HOME/.bash_history (and maybe others) because otherwise the command
>  could be found there. And I leave the encryption part as an exercise to
>  you because I'm too lazy to read it up myself :)
>  Nils

That's a cool trick. Going to flag this mail so i remember it.

/ Jonas

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