Shred

Shred is also a GNU command line utility to destroy data on a magnetic medium (hard disks or floppies).

This utility is the computer counterpart of a mechanical paper shredder.

It works by overriding several times (25 by default but you can use the -n argument to do it more times) your data with special data patterns designed to do the most damage on the original data.

You need to do this because; when you erase a file on most file systems, the data of the file isn't touched at all on the medium, only the file's entry on the directory is erased. Also, most magnetic mediums have a faint "ghost memory" of previously written data.

Beware, some kind of file systems do not override data in place (like NFS or journaled file systems), shred is useless on those, and it won't even display an error message.

Also, you must remember to destroy other copies of your data (like backups). And if you won't need the medium anymore, and your data is disclosure-sensitive enough or you're a paranoiac enough person, physically destroy the disk.

If you are planning to destroy a hard disk, do the following, unmount the protective hull (most hard disks have strange-headed screws, but you can use a drill), carefully dismount the step motors, the arm and the electronics board, and send them to me (so I can have some fun with them), and destroy the disk's plates. Just shredding them may not be enough, be sure to throughly destroy them, do not let any single piece of flat metal alive, melt them or acid burn them.

Shred (?), n. [OE. shrede, schrede, AS. scre�xa0;de; akin to OD. schroode, G. schrot a piece cut off, Icel. skrjo[eth]r a shred, and to E. shroud. Cf. Screed, Scroll, Scrutiny.]

1.

A long, narrow piece cut or torn off; a strip.

Bacon.

2.

In general, a fragment; a piece; a particle.

Shak.

© Webster 1913.

Shred, v. t. [imp. & p. p. Shred or Shredded (); p. pr. & vb. n. Shredding.] [OE. shreden, schreden, AS. scre�xa0;dian; akin to OD. schrooden, OHG. scrtan, G. schroten. See Shred, n.]

1.

To cut or tear into small pieces, particularly narrow and long pieces, as of cloth or leather.

Chaucer.

2.

To lop; to prune; to trim.

© Webster 1913.