use strict;
use warnings;
my %hash;
my $a = '1};print "You have just been cracked!\n";#a1:a2:a3=foo';
my ($key, $val) = split /=/, $a, 2;
$key =~ s/:/}{/g;
eval "\$hash{$key}=\"$val\"";
__END__
You have just been cracked!

##</code><code>##

use Data::Dumper;
$Data::Dumper::Terse = 1;
$Data::Dumper::Useqq = 1;

$key = join '}{', Dumper split /:/, $key, -1;