#!/usr/bin/perl

use strict;
use warnings;

use Digest::MD5 qw(md5);
use Data::Dumper;

my $salt='foo';
my @data = split('','abcdefghijklmnopqrstuvwxyz'); 
my @out = sort { md5($b.$salt) cmp md5($a.$salt) } @data;

print "output ".Dumper(\@out);