public function encryptValue($value)
    {
        $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
        $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
        $text = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $this->salt, $value, MCRYPT_MODE_ECB, $iv);

        return trim(base64_encode($text));
    }