<?php defined('BASEPATH') OR exit('No direct script access allowed');
class Login extends CI_Controller
{

function __construct()
{
    parent::__construct();
}

public function index()
{
    if($this->session->is_logued_in)
    {
        redirect(base_url().'dashboard');
    }
    else
    {
        $login = array(
            'title' => 'Powerby - Conviertete en un Aspirante',
            'name' => $this->security->get_csrf_token_name(),
            'hash' => $this->security->get_csrf_hash(),
            'script' => 'login.js'
        );

        $this->load->view('includes/header', $login);
        $this->load->view('login', $login);
        $this->load->view('includes/footer', $login);
    }
}

public function validate()
{
    $this->load->model('people_model', 'People', TRUE);

    $user = $this->input->post('_email');
    $password = $this->input->post('_password');

    $profile = $this->People->login($user);

    if($profile)
    {
        if (crypt($password, $this->session->_password) === $this->session->_password)
        {
            $this->session->set_userdata('is_logued_in', TRUE);
            $this->index();
        }
        else
        {
            $this->session->unset_userdata('is_logued_in');
            $this->session->set_flashdata('error_login', 'Verifique su contraseña.');
            redirect(base_url().'login', 'refresh');
        }
    }
}

public function salir()
{
    $this->session->sess_destroy();
    redirect(base_url().'login', 'refresh');
}
}

<?php defined('BASEPATH') OR exit('No direct script access allowed');
class People_model extends CI_Model
{

/*protected $id = NULL;
protected $name = NULL;
protected $last_name = NULL;
protected $user = NULL;
protected $password = NULL;*/

function __construct()
{
    parent::__construct();
}

/*public function __get($property)
{
    if (property_exists($this, $property))
    {
        return $this->$property;
    }
}

public function __set($property, $value)
{
    if (property_exists($this, $property))
    {
        $this->$property = $value;
    }
    return $this;
}*/

public function login($user)
{
    $this->db->select('*')
             ->from('people p')
             ->join('user u', 'u._id_PPL = p._id')
             ->where('u._user', $user);

    $query = $this->db->get();

    if($query->num_rows() == 1)
    {
        $this->session->set_userdata($query->row_array());
        return $query->row();
    }
    else
    {
        $this->session->set_flashdata('error_login', 'Verifique su usuario.');
        redirect(base_url().'login', 'refresh');
    }
}

public function create($params)
{
    $this->db->set($params);
    return $this->db->insert('people');
}
}

<?php defined('BASEPATH') OR exit('No direct script access allowed');
class Dashboard extends CI_Controller
{

function __construct()
{
    parent::__construct();
}

public function index()
{
    if($this->session->is_logued_in)
    {
        $header = array(
            'title' => 'Powerby - Panel de control '.$this->session->_name.' '.$this->session->_last_name
        );

        $this->load->view('includes/header', $header);

        $this->load->helper('form');

        $dashboard = array(
            'name' => $this->security->get_csrf_token_name(),
            'hash' => $this->security->get_csrf_hash()
        );
        $this->load->view('dashboard', $dashboard);

        $modal = array(
            'icon' => 'sign out',
            'modal_title' => 'Cerrando Sesión!',
            'modal_description' => 'Estas a punto de cerrar tu sesión de usuario, estas seguro de querer salir ahora?'
        );
        $this->load->view('includes/modal', $modal);

        $footer = array(
            'script' => 'dashboard.js|people.js'
        );
        $this->load->view('includes/footer', $footer);
    }
    else
    {
        $this->session->set_flashdata('sesion_cerrada', 'La sesión fue cerrada, ingrese de nuevo.');
        redirect(base_url().'login', 'refresh');
    }
}
}

$config['csrf_protection'] = TRUE;
$config['csrf_token_name'] = 'pbytoken';
$config['csrf_cookie_name'] = 'pbycookie';
$config['csrf_expire'] = 7200;
$config['csrf_regenerate'] = TRUE;
$config['csrf_exclude_uris'] = array();

$config['sess_driver'] = 'database';
$config['sess_cookie_name'] = 'pbysession';
$config['sess_expiration'] = 7200;
$config['sess_save_path'] = 'session';
$config['sess_match_ip'] = TRUE;
$config['sess_time_to_update'] = 300;
$config['sess_regenerate_destroy'] = FALSE;

$config['cookie_prefix']    = '';
$config['cookie_domain']    = '';
$config['cookie_path']      = '/';
$config['cookie_secure']    = FALSE;
$config['cookie_httponly']  = FALSE;

$this->session->set_userdata('is_logued_in', TRUE);
por esto:
$this->session->set_userdata('isloguedin', TRUE);