Exploring usability effects of increasing security in click-based graphical passwords

Graphical passwords have been proposed to address known problems with traditional text passwords. For example, memorable user-chosen text passwords are predictable, but random system-assigned passwords are difficult to remember. We explore the usability effects of modifying system parameters to increase the security of a click-based graphical password system. Generally, usability tests for graphical passwords have used configurations resulting in password spaces smaller than that of common text passwords. Our two-part lab study compares the effects of varying the number of click-points and the image size, including when different configurations provide comparable password spaces. For equivalent spaces, no usability advantage was evident between more click-points, or a larger image. This is contrary to our expectation that larger image size (with fewer clickpoints) might offer usability advantages over more clickpoints (with correspondingly smaller images). The results suggest promisin...

• Type: Journal
• Year: 2010
• Where: ACSAC
• Authors: Elizabeth Stobert, Alain Forget, Sonia Chiasson, Paul C. van Oorschot, Robert Biddle
• Keywords: ACSAC 2010, Graphical Password, Password, Security Privacy, Text Passwords