Re: Fun/Funny Fractal Encryption...

From	Richard Heathfield <rjh@cpax.org.uk>
Newsgroups	comp.lang.c
Subject	Re: Fun/Funny Fractal Encryption...
Date	2015-07-08 20:41 +0100
Organization	go, ion artisan!
Message-ID	<mnjual$uni$1@dont-email.me> (permalink)
References	(4 earlier) <mnid9r$g0i$1@speranza.aioe.org> <mnj1t4$77o$1@dont-email.me> <mnjp2c$o9r$1@speranza.aioe.org> <559D7019.9060406@verizon.net> <mnjsk1$1pg$1@speranza.aioe.org>

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On 08/07/15 20:10, Chris M. Thomasson wrote:
>>"James Kuyper"  wrote in message news:559D7019.9060406@verizon.net...
>
>
>>Because that formula is not unique. I've a strong background in math and
>>science, and that background tells me that there can be many different
>>ways of expressing the same thing.
>
> Ahhh. Well, that sort of implies that there is more than
> z = z^2 + c that can create the Mset,

No, it doesn't. Your program's output may have been derived from the 
Mandelbrot set, but that doesn't mean there isn't some other algorithm 
that will produce the same result /without/ deriving it from the 
Mandelbrot set.

Let me give you a simpler example, to illustrate the point. Alice writes 
a program to generate a keystream using a highly complicated algorithm: 
x[n] = f(x[n-1]) where f() is a scary function that returns a positive 
integer. As a final step, she uses the given value as an exponent to 5 
using her shiny new bignum package, and because she only needs a single 
digit she now reduces the value modulo 10, so the value actually used 
for encryption is 5^(x[n]) % 10.

Her keystream output (which she obviously didn't bother to check) is:

5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

It is not difficult to deduce the next number in the keystream without 
having to know anything at all about f().

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within

Thread

Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-07 17:08 -0700
  Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-08 01:12 +0100
    Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-07 17:19 -0700
      Re: Fun/Funny Fractal Encryption... Robert Wessel <robertwessel2@yahoo.com> - 2015-07-07 22:29 -0500
        Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-07 22:43 -0700
          Re: Fun/Funny Fractal Encryption... Robert Wessel <robertwessel2@yahoo.com> - 2015-07-08 03:23 -0500
          Re: Fun/Funny Fractal Encryption... James Kuyper <jameskuyper@verizon.net> - 2015-07-08 07:36 -0400
            Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-08 12:52 +0100
            Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-08 11:10 -0700
              Re: Fun/Funny Fractal Encryption... James Kuyper <jameskuyper@verizon.net> - 2015-07-08 14:46 -0400
                Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-08 12:10 -0700
                Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-08 20:41 +0100
                Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-09 09:55 -0700
                Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-09 11:18 -0700
                Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-09 19:25 +0100
                Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-09 13:49 -0700
                Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-09 22:09 +0100
      Re: Fun/Funny Fractal Encryption... Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-08 00:49 -0700
  Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-07 23:05 -0700
    Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-07 23:15 -0700
  Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-10 12:25 -0700
    Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-10 15:09 -0700
    Re: Fun/Funny Fractal Encryption... Richard Heathfield <rjh@cpax.org.uk> - 2015-07-15 15:52 +0100
    Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-31 13:40 -0700
      Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-31 13:43 -0700
        Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-07-31 13:46 -0700
      Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-08-21 14:45 -0700
        Re: Fun/Funny Fractal Encryption... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-08-22 01:29 +0100
          Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-08-21 20:03 -0700
            Re: Fun/Funny Fractal Encryption... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-08-22 13:02 +0100
              Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-08-22 18:15 -0700
    Re: Fun/Funny Fractal Encryption... "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-08-16 12:10 -0700
      Re: Fun/Funny Fractal Encryption... luser droog <luser.droog@gmail.com> - 2015-08-22 22:49 -0700

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