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Well, I'm Impressed

I found this at www.tpj.com. This is written in perl, and does encrption, decryption, and looks like a dolphin. This script didn't win the contest it was entered in, though I'm not sure how.
I am a fan of perl. I really like perl. I use perl daily. I am not nearly this good. I would like to congratulate Vipul Ved Prakash for... this thing.
- Kevin

Vial Stats

Author:         Vipul Ved Prakash. 
Contact:        mail@vipul.net

The Perl Code

#!/usr/bin/perl -s                          
                                                      sub R{int$_[0]||
                              return vec$_[1],$_[2]/4,32;int$_[0]*rand}($R)
                           =$^=~'([\]-\`])';sub F{$u=0;grep$u|=$S->[$_][$_[0]>>
                              $_*4&15]<<$_*4,reverse 0..7;$u<<11|$u>>21}$t=$e
                               ||$d?join'',<>:(($p,$d)=($R,1),unpack u
                               ,"(3=MCV7%2W'<`");@b=@t=0..15;for(
                           ;$i<length$p;$i+=4){srand($s^=R$R,$p
                        ,$i)}while($c<8){grep{push@b  ,splice
                     @b,R(9),5}@t;$R[$c]=R(2       **32);@{      
                $S->[$c++]}=@b}@h=0..7;@o       =reverse          
              @h;while($a<length
            $t){$v=R$R,$t,$a;
 $w=R$R,$t,($a+=8)-4;
   grep$q++%2?$v
    ^=F$w+$R                  
     [$$R]:(                                       $w^=F$v+$R[$$R]),$d?(@h,(@o)
     x3):((                                        @h)x3,@o);$_.=pack N2,$w,$v}
     print

What It Does

The code is a diminutive implementation of the KGB block cipher, GOST, in Simple Substitution Mode as described in the Soviet Standard (GOST 28147-89). An English translation by Josef Pieprzyk and Leonid Tombak is available from ftp://vipul.net/pub/gost/specs.ps.gz. (You don't really want to read this, a functional description of the algorithm is included in this file.)

Besides implementing the encryption algorithm, the code also also computes the key-store-unit and s-box permutations as a function of the pass-phrase.
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