public function authenticate(CakeRequest $request, CakeResponse $response) {
		App::uses('MtSites', 'MtSites./Utility/MtSites');

		// solo utilizar el logueo con PIN desde un Tenant
		if ( !MtSites::isTenant() ) {
			return false;
		}
		$userModel = $this->settings['userModel'];
		list(, $model) = pluginSplit($userModel);

		$fields = $this->settings['fields'];
		if (!$this->_checkFields($request, $model, $fields)) {
			return false;
		}
		return $this->_findUser($request->data[$model][$fields['pin']]);
	}