No Guide, No Cheat: Detecting Smart Glasses via AR Optical Signatures
Smart glasses are gaining increasing attention as they are expected to complement smartphones as next-generation mobile platforms, providing an Augmented Reality (AR) interface that bridges human experience and AI perception. With the goal of making smart glasses suitable for daily use, a new security risk has emerged: smart glasses can be used as cheating tools in competitions and exams when they are indistinguishable from regular glasses. This paper delves into this issue by exploring AR display mechanisms: a waveguide embedded in the lens of smart glasses transmits light from the temples of the glasses to the user’s eyes. Though the waveguide looks transparent from the front view, it induces AR displayed light leakage and unique light reflection patterns in a few other viewing angles. Motivated by this observation, we propose a new smart glasses detection method that exploits violations of the brightness constancy assumption in conventional optical flow methods to identify the unusual optical phenomena caused by the waveguide structure. Our preliminary experiments with three latest released smart glasses and three commonly seen regular glasses reveal that smart glasses can be detected in a non-invasive and privacy-preserving manner. This not only helps rebuild trustworthiness for smart glasses usage but also opens up new application opportunities that leverage AR unique optical signatures.
