http://www.perlmonks.org?node_id=469296

If you are unfamiliar with Kryptos, it is a sculpture by James Sanborn located on the campus of the CIA headquarters, located in Langley, VA. (Usually off limits to the general public) The sculpture, made in the shape of a scroll, holds a series of four encrypted messages. Although the code was intended by Sanborn to be decrypted by hand, only three of the four passages have been deciphered, and those only through machine aided cryptoanalysis. Credit for breaking the first three keys belongs to Jim Gillogly.

The code below does not embody any "cracking" functionality, it contains decryption algorithms that require the keys to function. The first two messages are encoded by character replacement algorithms called a Vigenere cipher. The third is encrypted by keyed columnar transposition and route transposition. The encryption method(s) used on the fourth passage have yet to be determined.

$nl=qr;\r*\n\r*;;sub __($@){join$?[0],@?[1..$#_];}sub _($;$){split$?[0 +],$?[1]||$?;} $m=qq|KRYPTOS${*?=*_;|x2;$m=~s[$nl];;;%dkeys=map{$?=>$m=~ m/($_.{26})/ +;}@tr=_$*,$m; $/=$*;@parts=map{[_ $nl,$_] ;}_ '_', <DATA> ;$#="edrkpyt"; su +b dekrypt{@c= map{_$,}@{$_[0]};$n=@p=_$*, $_[1]; $=%=$=;return __ '', map { +m"[A-Z]"? $tr [index$dkeys{$p[$=++%$n ]}, $?]: $_;}@c;}$#=~s/(.)(.)/$2$1/g; +sub ::{$l=@c= reverse map {_ $,}@{$_[0]}; $k =@k=_ $*,$_[1];$g=$?[2];$__c=$ +g%$k;$d=($k-1 )-$__c;$_r=($l-($d*$__c)) / $k;$__r=$_r+$d;@cr=();$kc=__ '', + sort {$a cmp $b}@k;@i=map{index$kc,$_; } @k ;@__c=(@i)[0..($__c-1)];for$x( +0..($k -1) ){ if(grep{$_ == $x}@__c) {for (1.. $__r){$cr[$x].=shift@c;}}else +{ for(1..$_r) {$cr[$x].=shift@c;}}}@g =() ;$g_= int($l/$g)+($l%$g>0);foreac +h$r(0..($k-1) ){for($x=0;$x<length($cr[$r ]);$x+= $g_){push@{$g[$r]},substr( + $cr[$r], $x, $g_);}}$gc=int($__r/$g_)+ ( $__r%$g_> 0);@l=();foreach $c (0 . +. ($g_- 1)) { foreach $g__ (0 .. ($gc - 1) ){ foreach $r (@i) {@l [$c] .= substr $g[ +$r] [$g__],$c ,1;}}} $ct = __ '', @l ; $ct =~ s/^(.)(.*)/$2$1/; return $ct;} }ABCDEF +GHIJLMNQUVWXZ sub : {print ${#}->( $parts[0], uc "palimpsest"), "\n\n"; print ${#}- +>( $parts [1] , uc "abscissa" ) , "\n\n"; print :: ( $parts [2] , uc "kryptos", 86), + "\n\n" ; } ; __DATA__ EMUFPHZLRFAXYUSDJKZLDKRNSHGNFIVJ YQTQUXQBQVYUVLLTREVJYQTMKYRDMFD_ VFPJUDEEHZWETZYVGWHKKQETGFQJNCE GGWHKK?DQMCPFQZDQMMIAGPFXHQRLG TIMVMZJANQLVKQEDAGDVFRPJUNGEUNA QZGZLECGYUXUEENJTBJLBQCRTBJDFHRR YIZETKZEMVDUFKSJHKFWHKUWQLSZFTI HHDDDUVH?DWKBFUFPWNTDFIYCUQZERE EVLDKFEZMOQQJLTTUGSYQPFEUNLAVIDX FLGGTEZ?FKZBSFDQVGOGIPUFXHHDRKF FHQNTGPUAECNUVPDJMQCLQUMUNEDFQ ELZZVRRGKFFVOEEXBDMVPNFQXEZLGRE DNQFMPNZGLFLPMRJQYALMGNUVPDXVKP DQUMEBEDMHDAFMJGZNUPLGEWJLLAETG_ ENDYAHROHNLSRHEOCPTEOIBIDYSHNAIA CHTNREYULDSLLSLLNOHSNOSMRWXMNE TPRNGATIHNRARPESLNNELEBLPIIACAE WMTWNDITEENRAHCTENEUDRETNHAEOE TFOLSEDTIWENHAEIOYTEYQHEENCTAYCR EIFTBRSPAMHNEWENATAMATEGYEERLB TEEFOASFIOTUETUAEOTOARMAEERTNRTI BSEDDNIAAHTTMSTEWPIEROAGRIEWFEB AECTDDHILCEIHSITEGOEAOSDDRYDLORIT RKLMLEHAGTDHARDPNEOHMGFMFEUHE ECDMRIPFEIMEHNLSSTTRTVDOHW?_OBKR UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO TWTQSJQSSEKZZWATJKLUDIAWINFBNYP VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR

-- So prophesied the shakespearean monkeys, and so it shall be.