ASCII Art and cryptography.

Hi all...

I've been doing a little bit of reading lately on cryptography and 'secret
writing' systems, particularly historical examples.  I'm looking more at
alphabetic substitutions and transpositions, human (de)codeable, not
complex mathematical algorithims.  Of course, both could be applied.

Anyways, it has occurred to me that ASCII pictures would be an ideal
method for concealing ciphered text.  An innocuous usenet posting or
signature line picture could easily contain an enciphered message.  I'm
going to try to come up with a few examples in the next while (and
hopefully some perl scripts), but in the meantime, has anyone else done
anything in this area?  Any URLs of interest?

Regards, 
Tony

-- 
# Anthony DeLorenzo <ajd...@sfu.ca>
# Burnaby, BC, Canada
# mojo wire: 209-391-8932
# http://www.sfu.ca/~ajdelore/

In alt.ascii-art, Anthony Delorenzo <ajd...@sfu.ca> wrote:
> Anyways, it has occurred to me that ASCII pictures would be an ideal
> method for concealing ciphered text.  An innocuous usenet posting or
> signature line picture could easily contain an enciphered message.  I'm
> going to try to come up with a few examples in the next while (and
> hopefully some perl scripts), but in the meantime, has anyone else done
> anything in this area?  Any URLs of interest?

Clinton A. Pierce wrote a program a while ago to embed sekret messages
into ascii art. He posted it to comp.lang.perl.misc in early Feb of
this year. A Google search (groups.google.com) should find the thread,
the subject line of the first message was "Apologies to Joyce Kilmer, a
hack for your enjoyment", and had this perl script:

#!/usr/bin/perl -w

                    '% * % % * % %<>
               * % ~ * % % * % * * % *      *
       * % % * *   % * % *<> * % ~   % % % * %
     *  * * % * % % % % * % % % % % % * % % * %
     % * % % ^ * % % % % *[] % % * * % * * % %  %
      % * %   % % % % % * * % * * @ *   @ % * % %
    % ^ % * % * % * * % % * %  <> % % % % * % %() %
  % % * * * % % * % % * * % * * * * % * * % % * * *
   %   * * * % % * % % *[]<> % % % % * % * * * % % *<>
 % * *  % % % * * % * * * \ * %\ * * *   %/ \ # % * *
  % % % *\ * /\ * *// %  %\ <>\ // % %/ % \// % * %
    * * *\ \|| \ \/ / % %// \ \ *\ /<> %//  %// % %<>
   * % * %\  \  |   | ||// % || //  \// % // * * * %
   %{} %  * ----\   \ | /   %||//   /  ---/ / * % % *
     % *  *\ ____\   \| |    /  /  /   /----/ * %
            \ ----\     |   /   //    /
                   \     \ /        /'
                    =~m/(.*)/s;$_=$1;
                     s![-\\|_/\s]!!g
                       ;%e=('%',0,
                       '^',132918,
                       '~'=>18054,
                       '@'=>19630,
                       '*' =>0b01,
                       '#'=>13099,
                       '[]'=>4278,
                       '<>'=>2307,
                       '{}'=>9814,
                       '()',2076);
                       for $a(keys
                       %e){$e{$a}=
                       sprintf"%b"
                       , $e{$a};}
                     $y= qq{(}.join(
                     '|',map "\Q$_\E"
                   ,keys %e).qq{)};s/$y
              /$e{$1}/gex;print pack"B*",$_;

__END__

If you run the script, it prints a message. The message is hidden
in the characters used for the leaves. If it used a solid stem,
instead of a program, then only someone who know to run a decoder
over it would find the message. 

Later on Clinton posted a script to take a message, and a peice
of ascii-art, and replace the 'fill' characters of the art to encode
the message in a new bit of ascii-art. Eg, replace solid 'O's with
a mix of 'O' and '0' to subtly hide the message.

Elijah
------
I think that I shall never see a program as lovely as a tree.