Towards User Re-Authentication on Mobile Devices via On-Screen Keyboard

Mobile devices have become our true companions in recent years. While bringing plenty of convenience, they also come with many security and privacy concerns. Being small, a mobile device is prone to loss or theft. Privacy data such as emails in a saved Gmail or Yahoo account on a lost device can be easily accessed by an unwanted visitor. Therefore, it is essential to research methods protecting mobile devices from any such unauthorized access. In this paper, we explore the potential of re-authenticating mobile device users by exploiting the biometrics derived from their tapping behaviors on the on-screen keyboard. We conduct an offline analysis on a dataset collected from 33 subjects using a Google Nexus S phone. The results show that more than 90% accuracy can be achieved for text input with 20 continuous key-taps.