Probably wouldn't be a bad idea to replace it with a md5 hash using Digest::MD5

use Digest::MD5;
my $hash = Digest::MD5->new();
$hash->addfile(*STDIN);
print $hash->hexdigest()."\n";
[download]

The resulting string is 4 times longer so its possible this would require adjustments elsewhere. You do however get the benefit of name recognition so anyone who comes across the code knows exactly what it is doing.