Evaluating Voxel-Based Graphical Passwords for Virtual Reality

Previous work has proposed using voxel-based graphical passwords (VGPs) for Virtual Reality (VR) as a secure, easy-to-remember way to authenticate users. Moreover, eye-tracking technology adds another level of security, as it avoids observational threats when entering the password. However, previous work has yet to evaluate the user performance, usability, and memorability of different combinations of VGPs. In two user studies, we first identified the best combination of shape and volume for VGPs. Then, we compare 3D versus 2D VGPs. Our results show that a cube is the best shape regarding usability and user preference. We also identified that 2D VGPs are easier to remember than 3D VGPs, as shown by a higher password accuracy and lower error rate. Our results inform the implementation of VGPs and other graphical passwords in VR.