PassGrid: Towards Graph-Supplemented Textual Shoulder Surfing Resistant Authentication

With the rapid development of intelligent mobile devices and network applications, user authentication plays an important role to help protect people’s privacy and sensitive information. A large number of authentication textual and graphical schemes have been proposed in the literature, but the majority of them are vulnerable to shoulder surfing attacks, or have to sacrifice usability. Motivated by this challenge, we propose a graph-supplemented textual shoulder surfing resistant authentication system, called PassGrid. With a series of one-time login indicators and cyclic movable blocks with textual elements, PassGrid prevents attackers from guessing the passwords even with the help of a camera. To reduce users’ workload, they only have to memorize one set of the password. Our user study shows that PassGrid can achieve good performance regarding security and usability, i.e., average login time consumption of 22s with a small password length.