Whenever you make registration form in Cakephp all you need to do is to make various field for username , email, password, gender etc etc... If you are inserting these values in the database then you should know that you should encrypt your password so that nobody could read it either you can use md5 encryption or either you can use blowfish hashing. Here we are discussing about the blowfish hashing.

In your AppController class you should write the below code:

<?php
class AppController {

    public $components = array(
        'Auth' => array(
            'authenticate' => array(
                'Form' => array(
                    'passwordHasher' => 'Blowfish'
                )
            )
        )
    );
}

Now to generate a password for password hasher you should write the below code in your model.

<?php
App::uses('BlowfishPasswordHasher', 'Controller/Component/Auth');

class User extends AppModel {

    public function beforeSave($options = array()) {
        // if ID is not set, we're inserting a new user as opposed to updating
        if (!$this->id) {
            $passwordHasher = new BlowfishPasswordHasher();
            $this->data[$this->alias]['password'] = $passwordHasher->hash($this->data[$this->alias]['password']);
        }
        return true;
    }
}

To authenticate your password you don’t really need to do anything because CakePHP have the predefine  function for authentication handler will do the password comparing for you:

<?php
class UsersController extends AppController {

    public function login() {
        if ($this->request->is('post')) {
            if ($this->Auth->login()) {
                return $this->redirect($this->Auth->redirectUrl());
            } else {
                $this->Session->setFlash( __('Username or password incorrect'));
            }
        }
    }
}

This is all you need to do encrypt your password using blowfish hashing.