Re: steganography

From: Louis Newstrom (
Date: Thu Sep 20 2001 - 12:55:18 MDT

----- Original Message -----
From: "Robert Coyote" <>
> then of course theres double-tripple dipping wher you encrypt with system
> then encrypt the result with system B and so on

This probably won't give you any more security.

For any substitution algorithm, replacing A with B and then replacing B with
C, is equivalent to just replacing A with C. You still have a substitution
code, no more secure than either of the original two.

For any transportation algorith, moving a bit from position A to B, then
moving the bit from position B to C, is eqivalent to moving the bit from A
to C. You still have a transportation code, no more secure than the
original two.

Modern encryption uses both transportation and substitution (although of
BITS, not discrete letters). Combining two encryptions just gives you a
third encryption, which is not any stronger than the first two encryptions.

> ----- Original Message -----
> From: "Eugene Leitl" <>
> To: <>
> Sent: Thursday, September 20, 2001 7:48 AM
> Subject: RE: steganography
> > On Thu, 20 Sep 2001, Harvey Newstrom wrote:
> >
> > > It's <> not <>, and I'm perfectly
> > > familiar with it. It is a very wonderful program and much more secure
> > > than other ones. But don't assume that it is "perfectly" secure.
> >
> > Duh. Perfect security is mythical, since infinitely expensive. In real
> > world, the bottlenecks lie most assuredly not in the cryptoattack and
> > cryptoanalysis region, so there's no point improving things there. You
> > have to start with the human factors.
> >
> > For all practical purposes, a public binary blob containing state of the
> > art steganography will a) never be recognized as such b) even if, the
> > strong cryptosystem used will not be broken within a time window counted
> > in decades.
> >
> >
> >

Louis Newstrom

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