A computer-implemented method for confirming identity of a user of a mobile electronic device having a touch-screen that captures user gestures and touch-data, the method comprising: (a) identifying that when a particular user performs a particular user gesture on a particular electronic device , the performance of said particular user gesture affects in a particular way the acceleration data and the orientation data of said electronic device , and extracting a user-specific behavioral trait from said acceleration data and said orientation data; (b) subsequently, distinguishing between the particular user and a second user of said particular electronic device , when the particular user or the second user performs a similar user gesture; wherein the method further deduces and utilizes, in order to assist in identification and/or authentication of the user, at least one more biometric trait out of the following: touch or swipe locations, pressure dynamics, identification of physiological regions that move while other regions do not move when a user gesture is performed; characterized in that the method comprises: based on said touch data, estimating user-specific motor control parameters and user-specific motor control noise of a control loop which comprises translation error and gesture velocity error; and based on the estimated user-specific motor control parameters and user-specific motor control noise, differentiating between said user and another user. (a) identifying that when a particular user performs a particular user gesture on a particular electronic device , the performance of said particular user gesture affects in a particular way the acceleration data and the orientation data of said electronic device , and extracting a user-specific behavioral trait from said acceleration data and said orientation data; (b) subsequently, distinguishing between the particular user and a second user of said particular electronic device , when the particular user or the second user performs a similar user gesture; wherein the method further deduces and utilizes, in order to assist in identification and/or authentication of the user, at least one more biometric trait out of the following: touch or swipe locations, pressure dynamics, identification of physiological regions that move while other regions do not move when a user gesture is performed; characterized in that the method comprises: based on said touch data, estimating user-specific motor control parameters and user-specific motor control noise of a control loop which comprises translation error and gesture velocity error; and based on the estimated user-specific motor control parameters and user-specific motor control noise, differentiating between said user and another user. touch or swipe locations, pressure dynamics, identification of physiological regions that move while other regions do not move when a user gesture is performed; characterized in that the method comprises: based on said touch data, estimating user-specific motor control parameters and user-specific motor control noise of a control loop which comprises translation error and gesture velocity error; and based on the estimated user-specific motor control parameters and user-specific motor control noise, differentiating between said user and another user. based on said touch data, estimating user-specific motor control parameters and user-specific motor control noise of a control loop which comprises translation error and gesture velocity error; and based on the estimated user-specific motor control parameters and user-specific motor control noise, differentiating between said user and another user. <EOS>