What is Blowfish Authentication:

It is an authentication adapter for AuthComponent. Blowfish is a symmetric-key block cipher. It provides the ability to authenticate Post Data using Blow Fishing. In order to add Blow fish authentication add it in Auth Component via AuthComponent::$authenticate settings.

Follow the steps below to add authentication using BlowFish.

Step1: In App Controller write following lines of code:

$this->Auth->authenticate = array(
        AuthComponent::ALL => array(
            'userModel' => 'User',
            'fields' => array(
                'username' => 'email',
                'password' => 'password'
            ),
            'scope' => $user_scope,
        ), 'Form'=> array(
                'passwordHasher' => 'Blowfish'
            )
    );

Step2: In Model write the following function:

   public function beforeSave($options = array()){
        if (isset($this->data[$this->name]['password'])) {
            $this->data[$this->name]['password'] = Security::hash($this->data[$this->alias]['password'], 'blowfish');
        }
        return true;
    }

Step 3: In Controller write following code:

  if ($this->Auth->login()) {
                    $this->redirect(array('controller' => 'admins', 'action' => 'dashboard', 'builder' => true));
                } else {
                    $this->Session->write('flash', array('You Have entered wrong username or password.', 'failure'));
                    $this->redirect(array('controller' => 'users', 'action' => 'login', 'builder' => true));
 }

Now run the web page, its all done!. You will see that password is encrypted in database.