Continuous Smartphone Authentication using Wristbands

Many users find current smartphone authentication methods (PINs, swipe patterns) to be burdensome, leading them to weaken or disable the authentication. Although some phones support methods to ease the burden (such as fingerprint readers), these methods require active participation by the user and do not verify the user’s identity after the phone is unlocked. We propose CSAW, a continuous smartphone authentication method that leverages wristbands to verify that the phone is in the hands of its owner. In CSAW, users wear a wristband (a smartwatch or a fitness band) with built-in motion sensors, and by comparing the wristband’s motion with the phone’s motion, CSAW continuously produces a score indicating its confidence that the person holding (and using) the phone is the person wearing the wristband. This score provides the foundation for a wide range of authentication decisions (e.g., unlocking phone, deauthentication, or limiting phone access). Through two user studies (N=27,11) we evaluated CSAW’s accuracy, usability, and security. Our experimental evaluation demonstrates that CSAW was able to conduct initial authentication with over 99% accuracy and continuous authentication with over 96.5% accuracy

Adaptive threshold scheme for touchscreen gesture continuous authentication using sensor trust

In this study we produce a continuous authentication scheme for mobile devices that adjusts an adaptive threshold for touchscreen interactions based on trust in passively collected sensor data. Our framework unobtrusively compares real-time sensor data of a user to historic data and adjusts a trust parameter based on the similarity. We show that the trust parameter can be used to adjust an adaptive threshold in continuous authentication schemes. The framework passively models temporal, spatial and activity scenarios using sensor data such as location, surrounding devices, wi-fi networks, ambient noise, movements, user activity, ambient light, proximity to objects and atmospheric pressure from study participants. Deviations from the models increases the level of threat the device perceives from the scenario. We also model the user touchscreen interactions. The touchscreen interactions are authenticated against a threshold that is continually adjusted based on the perceived trust. This scheme provides greater nuance between security and usability, enabling more refined decisions. We present our novel framework and threshold adjustment criteria and validate our framework on two state-of-the-art sensor datasets. Our framework more than halves the false acceptance and false rejection rates of a static threshold system