Implicit authentication for mobile devices using typing behavior

Abstract

An attacker that compromises the unlock mechanism of a mobile device can fundamentally use the device as if it were their own, with access to a large portion of the user’s sensitive data and communications. We propose a secondary implicit authentication scheme which monitors typing behavior to detect unauthorized use and lock down the mobile device. We build a basic implementation of our scheme on the Android operating system. Our user studies on the implementation show that we can achieve an accuracy of up to 97% identifying one user out of a set of fifteen, with an FAR of < 3% and an FRR of < .5%.