CakePHP has a complete feature to create a simple authentication or system login / logout. Although simple, but the quality of security sufficient for modern websites. If you want to learn to make the authentication system, please follow the tutorials available on this page. I also followed him, and succeeded perfectly.
However, there is a bit of a problem, that is, when you use a hash or encryption method different password other than blowfish. Yes, on the tuturial, cakephp using blowfish hash method. If you fill in the password by methods other than blowfish, then you will get an error like this.
Dont worry, the problem is not your system or cakephp or PHP version. However, for the PHP version, make sure you are using version 5.3 and above. I am using PHP version 5.5.3 and no problems.