From: John Stumbles <J.D.Stumbles@reading.ac.uk>
Date: Tue, 20 Feb 1996 00:51:25 +0800
To: cypherpunks <sasha1@netcom.com>
Subject: Re: CPF: Feb-17-1996.cpf
In-Reply-To: <199602170527.AAA20807@yakko.cs.wmich.edu>
Message-ID: <Pine.SOL.3.91.960219141852.9260F-100000@suma3.reading.ac.uk>
MIME-Version: 1.0
Content-Type: text/plain


On Sat, 17 Feb 1996, Damaged Justice wrote:

> Date: Fri, 16 Feb 1996 09:20:30 -0800
> From: sasha1@netcom.com (Alexander Chislenko)
> Subject: Re:  Computer unmasks Anonymous writer...
> 
>   I ran my essays through Word grammar checker a while ago,
> and was surprised how stable the grammar statistics were.
> Complexity of the text (grade level) was the same to the decimal point,
> average length of sentences was consistent, etc.
> People also use the same styles of smileys or *highlights*, make
> consistent spelling errors, have their habits of indentation, etc.
> 
> My suggestion at the time was to have randomizing output filter that
> would substitute synonyms, change spelling, modify paragraph formatting,
> etc.  - Style anonymizer, I'd call it.  Also, if small random changes are
> applied to every copy of the message you send out, and you keep track of
> what recipient got which version, you will find it easier to identify
> the leaks if you send private messages.  A dishonest recipient, to
> protect himself, would have to further randomize the message, which
> has apparent consequences for the ease of your identification and attributability of the message.

A similar method was (is?) allegedly used by H.M. Government depts (and no
doubt others) in restricted documents: the apparently even spacing of
letters along a line to acheive proportional spacing was in fact slightly
uneven and different on each copy, so a whistleblower (or spy) who
photocopied and leaked a document in their posession could be identified
if the copied document were examined. 


--
John Stumbles                                      j.d.stumbles@reading.ac.uk
Computer Services, University of Reading       http://www.rdg.ac.uk/~suqstmbl 
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Just pray that there's intelligent life somewhere out in space
 - because there's bugger all down here on earth!