In CakePHP, authentication is the process of identifying a user based on their credentials (such as a username and password). CakePHP provides a number of tools and features to help you implement authentication in your application.

Here are the steps you can follow to implement authentication in a CakePHP application:

1. Enable the CakePHP authentication plugin: The authentication plugin provides a set of components and behaviors that can be used to implement authentication in your application. To enable the plugin, add the following line to your application’s config/bootstrap.php file:

Plugin::load('Authentication');

2. Create the login and logout actions: You will need to create login and logout actions in your application’s controller to handle the authentication process. The login action should display a form for the user to enter their credentials, and the logout action should end the current user’s session.

3. Implement the authentication logic: You can use the authentication plugin’s AuthenticationComponent to handle the authentication logic in your controller. The component provides methods for checking the user’s credentials, logging the user in, and logging the user out.

4. Secure your application’s controllers and actions: You can use the AuthComponent to restrict access to certain controllers or actions to only authenticated users.

5. Create the login and logout views: You will need to create the login and logout views to display the login form and logout message to the user.

By following these steps, you should be able to implement authentication in your CakePHP application.

Note: These are just the basic steps for implementing authentication in CakePHP. There are many additional features and customization options available, such as handling password hashing and creating custom authentication adapters.