A Novel Hybrid User Authentication Scheme Using Cognitive Ambiguous Illusion Images

Text-based passwords are most common and easy to use but are difficult to memorize and remember. Moreover, they are prone to attacks like shoulder surfing and brute-force. On the other hand, graphical passwords are easy to remember and memorize. But they are still not commonly used as they have some issues like increased user login time, and small password space. In today’s scenario where number of data breaches is increasing, more secure authentication schemes are needed to ensure the authenticity of a user. In this paper, we propose a novel hybrid user authentication scheme by integrating both text-based and graphical password schemes to make authentication system stronger and resistant to attacks. Our scheme has two steps of authentication, in which at the first step, the user has to recognize and select his appropriate image among the blurred images and in the next step, the user has to enter the tag associated with the selected image. Only after successful completion of the two steps, the user is authenticated. The images used as a part of graphical password scheme are cognitive ambiguous illusion images. The basic idea behind using these images is that they are perceived by different users differently depending on how they visualize the image. To evaluate the effectiveness of the proposed scheme, an experiment was conducted on the setup and the results obtained were promising.