From: tcmay@got.net (Timothy C. May)
Date: Mon, 9 Oct 95 12:21:57 PDT
To: cypherpunks@toad.com
Subject: Re: PC wipe utilities
Message-ID: <ac9ec30f04021004c1ed@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


At 6:52 PM 10/9/95, Brian D Williams wrote:

>Alan Penny's  excellent freeware utility wipe.zip has been
>uuencoded and sent to you. I believe it fulfills your requirements.
>
> As recently as the last issue of WIRED an article by a data
>recovery company claimed they could recover data that had been
>overwritten nine times...... make it a bakers dozen to be safe.

Better yet, wipe the disk/diskette on _more than one_ machine. It should be
easy to just run the wipe on, say, 3 machines, 3 to 5 times each.

A lot of the ability to recover putatively erased media lies in the fact
that a given set of read-write heads has characteristics (especially with
regard to positioning) that make repeated erase passes less than fully
effective. The remnants of the recorded signal can be extracted with
careful analysis of the analog signal (especially from special read heads).

Using N erase machines increases the "jitter" to some extent.

My hunch is that it would make the recovery process exponentially (in N)
more difficult. But I have no lab experience in this, so this is just an
idea.

But crunching the media is a faster (and maybe cheaper) approach.


--Tim May

Views here are not the views of my Internet Service Provider or Government.
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
Corralitos, CA              | knowledge, reputations, information markets,
Higher Power: 2^756839      | black markets, collapse of governments.
"National borders are just speed bumps on the information superhighway."