Generar cadena aleatoria en PHP

public function cadenaAleatoria($length = 10)
{
	$characters='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
	$charactersLength=strlen($characters);
	$randomString='';
	
	for ($i=0;$i<$length; $i++)
	{
		$randomString.=$characters[rand(0, $charactersLength-1)];
	}

	return $randomString;
}