Caesar Shift Solution

WARNING "The Code Book" spoiler ahead

I'm sure quite a few of you guys have read/heard of Simon Singh's book The Code Book (if not it's well worth checking out).

Well here is my script that I used to crack the second puzzle in the book. It's nothing very elaborate but just in case anyone might be interested.

The code is

MHILY  LZA  ZBHL  XBPZXBL  MVYABUHL  HWWPBZ  JSHBKPBZ  JHLJBZ
KPJABT  HYJHUBT  LZA  ULBAYVU
[download]

and it's a Caesar Shift code
Here's the script

use strict;

open(CODE,"code2.txt");
my @code=<CODE>;
close(CODE);

my @alphabet = ("A".."Z");
my (%crypt);

foreach my $try_number (0 .. 26){
  print STDOUT "\n---- Shift of $try_number :\n";
  foreach my $letter (A .. Z){
    my $index= ($try_number++)%26;
    $crypt{$letter} = $alphabet[$index];
  }
  foreach my $code_line (@code){
    foreach my $letter_or_space (split(//,$code_line)){
      if ($letter_or_space =~/\s+/){
    #Got a space
    print STDOUT " ";
      }else{
    print STDOUT $crypt{$letter_or_space};
      }
    }
  }
}
print STDOUT "\n";
[download]

I also have a script for the first puzzle also if anyone is interested.

PS The script produces all the options you have to spot the correct solution. It should be pretty obvious :-)

Comment on Caesar Shift Solution Select or Download Code

Replies are listed 'Best First'.
Re: Caesar Shift Solution by japhy (Canon) on May 14, 2001 at 18:07 UTC
I hate to burst your bubble, but `tr///` is made for this sort of thing. `for (1 .. 26) { $str =~ tr/a-zA-Z/b-zaB-ZA/; print $str; }` [download] `japhy` -- Perl and Regex Hacker	[reply] [d/l]
Re: Caesar Shift Solution by tachyon (Chancellor) on May 17, 2001 at 08:45 UTC
FABER EST SUAE QUISQUE FORTUNAE APPIUS CLAUDIUS CAECUS DICTUM ARCANUM EST NEUTRON I really enjoyed this book. Have you cracked some of the harder ones? You could shorten your code quite a bit like this, not that it really matters tachyon `use strict; my @code=<DATA>; my $code = join'', @code; my @alphabet = ("A".."Z"); my (%crypt); for my $try(0..26){ print "\n---- Shift of $try :\n"; for(A..Z){ my $index= ($try++)%26; $crypt{$_} = $alphabet[$index]; } for my $letter(split //,$code){ ($letter =~/\s+\|\n/)? print " " :print $crypt{$letter}; } } print "\n"; __DATA__ MHILY LZA ZBHL XBPZXBL MVYABUHL HWWPBZ JSHBKPBZ JHLJBZ KPJABT HYJHUBT LZA ULBAYVU` [download]	[reply] [d/l]