From: tcmay@got.net (Timothy C. May)
Date: Sat, 7 Sep 1996 14:49:54 +0800
To: cypherpunks@toad.com
Subject: Re: What the NSA is patenting
Message-ID: <ae56437706021004a769@[207.167.93.63]>
MIME-Version: 1.0
Content-Type: text/plain


At 12:50 AM 9/7/96, Jean-Francois Avon wrote:
>A maybe usefull program would be a little tsr that constantly
>overwrite unused sectors of the entire drive with random patterns
>(maybe seeded with a fast keyboard interval timer).  Like at the very
>moment I am writing this, my HD has been idle for several minutes...
>


The NSA STM method is related to reading _very subtle_ variations in
magnetic domain modifications. Jitter in read-write head positions can be
thought of as a noise (N) added to some signal (S)l. Extraction of signals
in low S/N ration environments is a well-developed science.

Not to start another round of "thermite bomb" posts, but I would not trust
n-pass erasures.

Of course, this is about the least of my concerns. If the Feds are planning
to use STM probes on your seized drives, you've got more serious problems.

(The oft-discussed possibility of more secure dongles, or secret decoder
rings. is still off in the future. Most of us just enter our various
passwords, and our local disk drives reveal all.)

--Tim May

We got computers, we're tapping phone lines, I know that that ain't allowed.
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
W.A.S.T.E.: Corralitos, CA  | knowledge, reputations, information markets,
Higher Power: 2^1,257,787-1 | black markets, collapse of governments.
"National borders aren't even speed bumps on the information superhighway."