Abstract
In this bachelor thesis we propose a new form of user authentication based on images. We present a system in which a user logs in by clicking on a sequence of specific points in an image. In contrast to earlier work the user is not presented the same picture every time he logs in. He sees a new random picture showing the same object from a different viewing angle and in a changed illumination. We present an analysis of the security of the system. We further present a user study showing the usability of the system. Participants used the system to create an own password and to login with their password.