From: Damien Lucifer <root@HellSpawn>
Date: Thu, 29 Aug 1996 12:14:02 +0800
To: stewarts@ix.netcom.com
Subject: Re: Mimic Function Stego Programs?
In-Reply-To: <199608282111.RAA17052@cbig1.att.att.com>
Message-ID: <Pine.LNX.3.91.960828213126.4972A-100000@HellSpawn>
MIME-Version: 1.0
Content-Type: text/plain


On Wed, 28 Aug 1996 stewarts@ix.netcom.com wrote:

> Mimic Functions?  I'm looking for something that you can hand a grammar
> and a set of bits that will produce sentences in the grammar,
> plus a decoder that can take the sentences and reconstruct the bits.


I think Texto is what you are looking for, and it is available from the 
cypherpunks archive in the steganography directory. If you can't find it, 
drop me a private note and I'll mail it to you...

A quick outline of its function:

It uses a file full of Mad-Lib type sentence blanks, and a dictionary 
full of words arranged by type (person, place, thing, verb, etc). 
There are 64 words of each type which correspond to the 64 ascii symbols 
used in pgp ascii armor, or alternately, the 64 symbols used by standard 
uuencode.

The sentence structures look like:

The _THING _VERBs to the _PLACE.

It selects an appropriate word type for the particular blank it needs to 
fill, and inserts the word corresponding to the symbol in the data to be 
hidden.

Extracting the data from the resulting text is pretty straightforward:
All words that don't appear in the dictionary file are discarded. The 
words that remain are mapped back to their corresponding sybols. 

You can expect your data to grow to 10 times its original size in the 
process of steg'ing, and you'll have to ascii armor or uuencode the data 
before it can be stegged by this program, but its clever, and might fool 
a simple filter-bot or other program, although its doubtful it would ever 
fool a person. 



ciao