Re: art-stego

Jonathan Rochkind wrote:

> So a good steganography algorithm (which I understand
> exists) merely changes the values of the noise so that it
> now encodes your (random) message.  So there's no way to
> look for "suspicious
 bit patterns"
> 


You are assuming that the noise bits have the same statistical properties  
as cyphertext.  I would be very surprised if this were the case.  It takes  
special effort to achieve good random bit streams.  Image scanners may do  
this by accident, but then again, maybe they don't.  This uncertainty is,  
in my opinion, the fatal flaw in image-based steganography.  The same  
reasoning applies to audio-based steganography.  Unless the devices were  
specially designed to insert cryptagraphically useful bits in the output  
(or, as Tim May suggested, good garbage bits are inserted later), then you  
should not rely on the pictures or audio files to keep your messages  
hidden.

As an alternative to trying to hide bits, I proposed not hiding them at  
all, but instead creating an innocent reason for passing around files that  
contain, in some way or another, obvious random bit streams.  The first  
idea that came to mind was to use the random bit streams to create pretty  
fractal pictures.  I soon realized that any function that produces pretty  
pictures would do the trick as long as there was a way to recover the  
random bit stream given only the picture and the function.  Perhaps it  
would be possible to use random bit streams to generate cool BioMorphs  
(ala "The Blind Watchmaker").

If enough people start passing around pictures generated from meaningless  
random bit streams, then other people could use this traffic to covertly  
exchange pictures generated from meaningful random bit streams.


> if they can manage to get a cleartext message out of it,
> plausible deniability is unlikely to get you far. 

> 

You could always claim you didn't know it was there, that you just  
downloaded the picture out of curiosity.  It might help, depending on what  
country you live in.



Tim May wrote:

> Just bear in mind that this form of steganography is
> getting further away from conventional hiding, and
> into "pure plausible deniability." In fact, one need
> not even make a serious attempt to hide the encrypted
> bits: just call the encrypted file "art" and be done with
> it! 

> 


Come to think of it, if the picture files were larger than the random bit  
streams, people very well might send just the random bit streams.

"Hey Bob, take a look at the picture this creates when you feed it to the  
XYZ function (coefficient values A, B, and C)."


Jim_Miller@suite.com


P.S. In case anyone is wondering, the reason there is a large delay  
between a post from me and a reply from me is that I'm not actually on the  
mailing list.  I read the messages by pointing my news reading at  
nntp.hks.net

Delurking beginner...
1)	Is it possible to base a privacy key ( e.g. PGP ) on a fractal 
		equation, instead of an algorithm based on two primes?  
		This would allow for an eternal level of complexity due 
		to infinite field of depth one can find as one 'zooms in' 
		closer ( correct me because I'm wrong; I'm not a math major,
		although increasingly I wish I was... ), allowing for near
		unbreakable privacy of information.
2)	It is dead certain that our governments will want at their disposal 
		a decrypt program to crack into data containing information
		possibly related to crimes ( or what not ).  Perhaps access 
		to this program can somehow be leased out like a search warrant
		by a judge, which at least means a check and balance, and any 
		unauthorized use of the program ( perhaps when it cracks into 
		encryptext [ what I call ciphertext, as opposed to uncryptext, 
		or plaintext ;) ] it leaves a very characteristic signature, or 
		cracking into the database that contains the program is near
		impossible; maybe it's not physically connected to the 
		Internet until the warrant is granted ) results in punishment,
		of course.
Back to lurking...
	 
							Sincerely.
							Quentin Holte.
							( aka Charles Choi. ) 
							
							You are all the Buddha.
								- Last words
								  of Buddha.

							If you see the Buddha,
                                            		             kill him.
                                                                - Zen proverb.

-----BEGIN PGP SIGNED MESSAGE-----

On Tue, 5 Mar 1996, Charles Choi (SAR) wrote:

> 1)	Is it possible to base a privacy key ( e.g. PGP ) on a fractal 
> 		equation, instead of an algorithm based on two primes?  
> 		This would allow for an eternal level of complexity due 
> 		to infinite field of depth one can find as one 'zooms in' 
> 		closer ( correct me because I'm wrong; I'm not a math major,
> 		although increasingly I wish I was... ), allowing for near
> 		unbreakable privacy of information.

The fact that the private key is based on fractals rather than prime numbers
really doesn't make a difference.  Fractals are not random, and do in fact,
have a pattern.  The Mandelbrot Set, for instance, can be expressed in a
few bytes of information even though it is infinitely complex.  Therefore,
the fractal has extremely low entropy making it a bad choice from which to
obtain random data.

- --Mark

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
markm@voicenet.com              | finger -l for PGP key 0xf9b22ba5
http://www.voicenet.com/~markm/ | bd24d08e3cbb53472054fa56002258d5
"The concept of normalcy is just a conspiracy of the majority" -me


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Decloaking...
Assumption 1 : a privacy key can become uncrackable.
Assumption 2 : an individual signature can become immune to fraud.
Posit : fuse the two together so that pseudonyms/aliases/online names ensure 
		complete privacy, but ensure that you talk to the same person
		everytime.  
Probably proposed already.
Cloaking...

							Sincerely.
							Quentin Holte.
							( aka Charles Choi. ) 
							
							You are all the Buddha.
								- Last words
								  of Buddha.

							If you see the Buddha,
                                            		             kill him.
                                                                - Zen proverb.

Hi,

> Assumption 1 : a privacy key can become uncrackable.
> Assumption 2 : an individual signature can become immune to fraud.
> Posit : fuse the two together so that pseudonyms/aliases/online names ensure 
> 		complete privacy, but ensure that you talk to the same person
> 		everytime.  
> Probably proposed already.

Unforutnately both of your assumptions are wrong.  A key cannot be
100% uncrackable, and a signature cannot be 100% immune to fraud.
With electronic security, there is always a chance that a key can be
cracked or a signature forged.  The question is how hard is it to
crack the key or forge the signature?  You need to balance the
security with the price.

For example, a 1024-bit RSA key cannot be cracked, today, in a
reasonable amount of time.  However it is unclear how long that will
last.  Look at RSA-129; in 1977 Ron Rivest said it would take 40
quadrillion years to break the key.  In 1993-4 it took 8 months (5000
MIPS-years).

A key has a limited size, therefore it is theoretically possible to
try every single key (this is called brute-force).  Therefore it is
impossible to have 100% uncrackable keys.  Singatures have the same
problem.

Enjoy!

-derek