Have you permission to answer this phone?

The new frontier of biometric authentication exploits wearable sensors. At present, there is no need of special equipment. Both cameras of increasing resolution, and MEMSbased sensors (Micro Electro-Mechanical Systems) are ubiquitously embedded in everyday mobile communication devices, especially smartphones. This makes their use economically attractive, and the investigation of the new provided possibilities increasingly widespread. The aim of the present paper is to demonstrate the possibility to control the access to a smartphone by recording and processing the dynamic signals produced by the simple gesture of lifting the phone, possibly in connection with further biometric information provided by ear recognition. In this respect, it continues and extends a previous work, by performing new experiments on a more challenging dataset.