Secure environments protect their resources against unauthorized access by enforcing access control mechanisms. So when increasing security is an issue text based passwords are not enough to counter such problems. This is where Image Based Authentication (IBA) comes into play. IBA enhances the security level in an exceptionally user friendly way. This paper is a comprehensive study and comparison of proposed Jaypee University of Information Technology–IBA System with the University of Florida–IBA System on the subject of using images as the password set. Furthermore the paper introduces a holistic view of Completed Finite State Automation (CFSA) modeling that can be carried out as a complementary step to system modeling, enabling a precise scalability of the test process, revealing much rationalization potential. Finite-state based notions enable to introduce efficient algorithms to generate Legal Interaction Pairs (IPs), Faulty Interaction Pairs, and Regular Expression (RegEx).