You can use Tie::Hash::Array to ensure that a hash is sorted.
Added:
Limbic~Region brought up that you need a hash of hashes sorted. Here is a simple example of how to use this with Data::Dumper.

use Tie::Hash::Array;

tie my %hash, 'Tie::Hash::Array';

foreach(a..z){
    tie my %tmp, 'Tie::Hash::Array';
    my $t = $_;
    foreach my $i(0..5){
        $t++;
        $tmp{$t} = $i;
    }
    $hash{$_} = \%tmp;
}

use Data::Dumper;
print Dumper \%hash;

untie %hash;

__OUTPUT__

$VAR1 = {
          'a' => {
                   'b' => 0,
                   'c' => 1,
                   'd' => 2,
                   'e' => 3,
                   'f' => 4,
                   'g' => 5
                 },
          'b' => {
                   'c' => 0,
                   'd' => 1,
                   'e' => 2,
                   'f' => 3,
                   'g' => 4,
                   'h' => 5
                 },
          'c' => {
                   'd' => 0,
                   'e' => 1,
                   'f' => 2,
                   'g' => 3,
                   'h' => 4,
                   'i' => 5
                 },
          'd' => {
                   'e' => 0,
                   'f' => 1,
                   'g' => 2,
                   'h' => 3,
                   'i' => 4,
                   'j' => 5
                 },
          'e' => {
                   'f' => 0,
                   'g' => 1,
                   'h' => 2,
                   'i' => 3,
                   'j' => 4,
                   'k' => 5
                 },
          'f' => {
                   'g' => 0,
                   'h' => 1,
                   'i' => 2,
                   'j' => 3,
                   'k' => 4,
                   'l' => 5
                 },
          'g' => {
                   'h' => 0,
                   'i' => 1,
                   'j' => 2,
                   'k' => 3,
                   'l' => 4,
                   'm' => 5
                 },
          'h' => {
                   'i' => 0,
                   'j' => 1,
                   'k' => 2,
                   'l' => 3,
                   'm' => 4,
                   'n' => 5
                 },
          'i' => {
                   'j' => 0,
                   'k' => 1,
                   'l' => 2,
                   'm' => 3,
                   'n' => 4,
                   'o' => 5
                 },
          'j' => {
                   'k' => 0,
                   'l' => 1,
                   'm' => 2,
                   'n' => 3,
                   'o' => 4,
                   'p' => 5
                 },
         ....
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- Tom