What You See is Not What You Get

Smart glasses are becoming popular for users to access various services such as email. To protect these services, password-based user authentication is widely used. Unfortunately, the password-based user authentication has inherent vulnerability against password leakage. Many efforts have been put on designing leakage-resilient password entry schemes on PCs and mobile phones with traditional input equipment including keyboards and touch screens. However, such traditional input equipment is not available on smart glasses. Existing password entry on smart glasses relies on additional PCs or mobile devices. Such solutions force users to switch between different systems, which causes interrupted experience and may lower the practicability and usability of smart glasses. In this paper, we propose a series of leakage-resilient password entry schemes on stand-alone smart glasses, which are gTapper, gRotator, and gTalker. These schemes ensure no leakage in password entry by breaking the correlation between the underlying password and the interaction observable to adversaries. They are practical in the sense that they only require a touch pad, a gyroscope, and a microphone which are commonly available on smart glasses. The usability of the proposed schemes is evaluated by user study under various test conditions which are common in users' daily usage. The results of our user study reveal that the proposed schemes are easy-to-use so that users enter their passwords within moderate time, at high accuracy, and in various situations.