A Multi-Grid Graphical Password Scheme

The vast majority of computer and communication systems use passwords in order to identify users. Unfortunately, in ubiquitous alpha-numeric password schemes, users tend to choose passwords with predictable characteristics, related to how easy they are to remember. To overcome the vulnerabilities of textual passwords, a lot of alternative techniques have been proposed such as visual or graphical login, biometric systems and fingerprint verification. In this paper we focus on graphical password techniques and more specifically we make an extension to the Draw-a-Secret scheme (DAS) proposed by Jermyn et al. (1999). On the simple DAS scheme the user draws a design on a display grid, which is used as the password. Motivating by the fact that users tend to draw lines and shapes on specific areas in the grid, we propose a different multi-grid construction of the DAS technique. By making a survey on a sample of people with different age and technical knowledge, we concluded that this approach increases the password strength, while remaining user-friendly.