From: tcmay@netcom.com (Timothy C. May)
Date: Thu, 11 Mar 93 13:23:51 PST
To: cypherpunks@toad.com
Subject: Re: HIDE: embedding msgs into snd & graphics
Message-ID: <9303112122.AA00150@netcom.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


Matt Thomlinson writes:

>The idea of using a DAT tape as a mode of transport, however, doesn't
>appeal that greatly to me. To send a message, I have to pull out one of my
>prevoiusly recorded DAT host-tapes, then record over the 5th song with my
>mix of host/message pair, then fed-ex it (or hand-deliver it) to my
>target. If I take this signal and push it across internet, I no longer
>have the passive-looking DAT tape in my DAT music collection. Instead, I
>have a 900k sound file that I push across the net. Since the net is
>usually not used to push the latest Michael Jackson tune, it might raise a
>flag. 
>
>Tim's comments are valid and definitely help solve problems on the
>physical level: now how about cyberspace?

Granted, a DAT can carry more data in the LSBs--about 80 MB, about the
length of 10 Bibles--than one really needs.

The GIF option I mentioned allows a widely disseminated image file to
contain about 32 KB in just the LSBs of a 512 x 512 x 8-bit gray scale
image. A color image could easily hold three times more (LSBs in each color
channel). And some GIFs are much larger than 512 on a side.

So, a fairly long message could be inserted into the "noise floor" bits of
a scanned or frame-grabbed image, or of a piece of "original art" and then
posted worldwide in one of the GIF groups. Who knows what evil messages are
even now being sent in GIFs of Cindy Crawford and Claudia Schiffer?

Use your imagination and you'll see there are several other easy ways to
hide messages. (Again, we're talking steganography--check the "Glossary" in
the soda.berkeley.edu archives if this is new to you.)

-Tim May
--
Timothy C. May               | Crypto Anarchy: encryption, digital money,  
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