protected function _init()
    {
        if (!isset($this->_ob) ||
            ($this->_ob->md5 != hash('md5', $this->key))) {
            switch ($this->cipher) {
            case 'cbc':
                $this->_ob = new Horde_Crypt_Blowfish_Php_Cbc($this->key);
                break;

            case 'ecb':
                $this->_ob = new Horde_Crypt_Blowfish_Php_Ecb($this->key);
                break;
            }
        }
    }