Path Word: A Multimodal Password Entry Method for Ad-hoc Authentication Based on Digits' Shape and Smooth Pursuit Eye Movements

We present PathWord (PATH passWORD), a multimodal digit entry method for ad-hoc authentication based on known digits shape and user relative eye movements. PathWord is a touch-free, gaze-based input modality, which attempts to decrease shoulder surfing attacks when unlocking a system using PINs. The system uses a modified web camera to detect the user's eye. This enables suppressing direct touch, making it difficult for passer-bys to be aware of the input digits, thus reducing shoulder surfing and smudge attacks. In addition to showing high accuracy rates (Study 1: 87.1% successful entries) and strong confidentiality through detailed evaluations with 42 participants (Study 2), we demonstrate how PathWord considerably diminishes the potential of stolen passwords (on average 2.38% stolen passwords with PathWord vs. over 90% with traditional PIN screen). We show use-cases of PathWord and discuss its advantages over traditional input modalities. We envision PathWord as a method to foster confidence while unlocking a system through gaze gestures.