From: Jim Choate <ravage@ssz.com>
Date: Mon, 19 Jan 1998 09:07:35 +0800
To: cypherpunks@ssz.com (Cypherpunks Distributed Remailer)
Subject: CAD Stego (fwd)
Message-ID: <199801190137.TAA19440@einstein.ssz.com>
MIME-Version: 1.0
Content-Type: text



Forwarded message:

> Date: Sun, 18 Jan 1998 19:31:38 -0500
> From: John Young <jya@pipeline.com>
> Subject: CAD Stego

> This repeats a suggestion from 1994 about using computer
> assisted design programs to conceal text or other data:

> 3. The scale feature is useful to reduce, say, a text
> of any length, or any digital object, to the size of a pixel. 

Assuming your color palate is deep enough to support the compression.

> 4. Or, the text can be distorted by scale and dimension
> to appear to be a line serving another function.

Don't you think they are going to wonder why *that* line is so varied in
color? Or assuming deep color pallettes, why so many colors are selected
when only a few dozen are actualy used in the drawing?

> Then the message could be distorted or hidden as
> described above, for piggy-backing on an innocent-
> looking document issued,

I suspect they'll wonder why that particular file is so much larger than
the other graphics files with the same number of layers.

> 7. Big shortcoming: how to securely transmit the location 
> (virtual coordinates) of the hidden message and what 

Look for the pixel that has the unique color mapped onto it.

> 8. Medium shortcoming: Full-featured CAD programs are 
> expensive, however, the popular lite versions are cheap
> and can usually read the pricier output.

And can't handle more than a few dozen colors and limited layering.

This suggestion is unworkable in application.


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