[8429] in cryptography@c2.net mail archive
Re: NONSTOP Crypto Query
daemon@ATHENA.MIT.EDU (Ray Dillinger)
Fri Jan 12 17:38:32 2001
Date: Fri, 12 Jan 2001 13:37:38 -0800 (PST)
From: Ray Dillinger <bear@sonic.net>
To: John Young <jya@pipeline.com>
Cc: cryptography@c2.net
In-Reply-To: <200101121702.MAA07450@blount.mail.mindspring.net>
Message-ID: <Pine.LNX.4.21.0101121332370.30585-100000@bolt.sonic.net>
MIME-Version: 1.0
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On Fri, 12 Jan 2001, John Young wrote:
>Wright also describes the use of supersensitive microphones
>to pick up the daily setting of rotors on cryptomachines of the
>time, in particular the Hagelins made by CryptoAG.
Hmmm. That sounds like a trick that could be brought up to
date. If you get two sensitive microphones in a room, you
should be able to do interferometry to get the exact locations
on a keyboard of keystrokes from the sound of someone typing.
I guess three would be better, but with some reasonable
assumptions about keys being coplanar or on a surface of known
curvature, two would do it. Interesting possibilities.
Bear
[A quick contemplation of the wavelength of the sounds in question
would put an end to that speculation I suspect. --Perry]
